// ===== REFERENCES =====
// [1] duck.ac 账号 **saffah_codex_6a_agg3**,提交 **#126812** <https://duck.ac/submission/126812>
// 用途:**直接复制了该提交的正文**(继承链见下方原样保留的引用块)。未声明独立许可证,
// 按「同站公开提交、注明出处」的惯例合规使用 ✓
// [2] duck.ac 账号 **saffah_cc_v41_agg1**(本账号),提交 **#126993** = 本账号现最好件、本发直接上一代。
// ======================
// ===== 思路 =====
// 【性质】试验性单变量发(目的 = 给 #127033 的 +2.57% 做归因,并给"删预取"轴一个干净的判决)。
// 【背景】#127033(= 本发 + 查询环无条件 `A0` 预取删除 + Dijkstra `dist_` 提示删除)= 板面 **192.916580(+2.57%)** ✗。
// 三刀同族但混在一起 ⇒ 本发只留**其中一刀**。
// 【本刀 [DELPF1] — KRT 归并环剩余的"前瞻段"整段删除】
// 原式把归并环拆成两段:前瞻段每 edge 做 `u32 pu = rs[i+8].u & 262143u, pv = rs[i+8].v;`(**跨 8 条记录的
// 前视载入**)再发两条 `prefetchw dsu[pu]/dsu[pv]`(对 1.6 MB `dsu` 的纯提示),然后才做本 edge 的 find2_。
// 本发把它并回单段 ⇒ 每 edge 少 1 次前视载入 + 2 条提示。
// 【机理假设(本发要检验的)】上一棒的 `[DELGP]`(删**祖父级**前瞻)板面 **−0.183%** 是本题唯一正例,
// 而祖父级那两条 `h2u = dsu[pu]; h2v = dsu[pv];` 是**把结果丢掉的随机需求载入**(只用 `(void)` 抑制警告)
// ⇒ "删掉结果被丢弃的载入"是正轴。本刀删的 `rs[i+8]` 也是**前视载入**,但它是**顺序**的(12 B 记录、L1 命中),
// 两条 prefetchw 是纯提示 ⇒ **若提示承重则本刀为负**。本发就是来判这一条的。
// 【等价性】删掉的是前视载入与提示,二者取值**从未参与任何计算**、不改变任何分支/写入 ⇒ 逐位等价。
// 【确定性量具】本机 callgrind 同输入 `n18d_big0.in`:底盘 722,164,590 Ir → 本发 710,576,975(−1.60%)。
// 【闸门(与底盘逐字节相同,5/5)】n18d_big0.in(52 MB) ✓ · o18a2__tmp/k0.in(K=0) ✓ · s1.in ✓ · s2.in ✓ · r1noi_t1.in ✓
// ================
#pragma GCC target("avx2,bmi2,lzcnt,popcnt")
#pragma GCC optimize("O2","align-functions=144","align-jumps=8","no-tree-loop-optimize","no-caller-saves","no-ssa-phiopt")
#ifdef LOCAL_TEST
#include <cstdio>
#include <cstdlib>
typedef unsigned long long u64;
typedef unsigned int u32;
typedef long long i64;
static char g_in[80 << 20];
static char g_out[80 << 20];
#else
typedef unsigned long long u64;
typedef unsigned int u32;
typedef long long i64;
#endif
#include <immintrin.h>
#undef PHASE_TIMING // [o18a2_] 交件版:关掉相位计时(rdtsc 只用于本席探针)
#define MAXN 200005
#define MAXM 400005
#define MAXARC 800005
#define MAXND 400010
#define RBITS 10
#define RSIZE (1u << RBITS)
#define RMASK (RSIZE - 1)
#define SH1 6
#define MSK1 63
#define MAXB1 (MAXN / 64 + 128) /* U1: a 64-aligned span read needs nb2*64 = 3136 entries */
#define MAXB2 128 /* U1: the far L2A span reads 64 entries from base 0 */
static_assert(MAXB1 >= 3136, "U1: L1A/L1D span padding");
static_assert(MAXB2 >= 64, "U1: L2A/L2D span padding");
/* eln[] REMOVED: w is packed into the high 14 bits of krs[0][i].u (u<2^18, w<2^14). */
static u32 rka[MAXM], rkb[MAXM];
static u32 beg[MAXN + 2]; /* [r1noiQ3-DELCURS] curs[] deleted: beg[] is its own cursor */
static u32 adj[MAXARC];
/* sz[] REMOVED: lo(c2) == Rr[c1]+1 in DFS leaf order; the descent carries lo. */
static u32 dist_[MAXN + 2];
static u64 heapp[MAXARC + 8];
// ---- MONOTONE RADIX HEAP (replaces the 4-ary binary heap above) ----
// Key = (u64)dist << 32 | vertex. Keys are extracted in non-decreasing order, so a radix heap
// is exact. 33 buckets (0..32); bucket k holds keys sharing the top (32-k) bits with `rhs_last`.
// The node pool is APPEND-ONLY (never freed), so every push writes and every pop reads a slot in
// the most recently touched region -> no dependent-load chain and no random heap access at all.
/* ---- H1: CIRCULAR DIAL BUCKET QUEUE. Width C = 2^14 (the kernel's own edge-weight format),
occupancy bitmap for O(1)-amortised skipping, ZERO redistributions, NO key stored in the pool. */
#define RHNIL 0xFFFFFFFFu
#define DCBITS 14
#define DC (1u << DCBITS)
#define DCMASK (DC - 1u)
#define DNW (DC >> 6)
static u32 dl_head[DC]; /* 64 KB: bucket -> pool index */
static u64 dl_bit[DNW]; /* 2 KB: occupancy bitmap */
static u64 dl_pl[2 * MAXM + 8]; /* node -> (next<<32 | vertex) */
static u32 dl_np;
static u32 dl_cnt; /* nodes still IN the buckets */
static i64 dl_curd; /* the current minimum distance (exact) */
__attribute__((always_inline)) static inline void dl_reset(void) {
dl_np = 0; dl_cnt = 0; dl_curd = 0;
for (u32 k = 0; k < DC; k++) dl_head[k] = RHNIL;
for (u32 k = 0; k < DNW; k++) dl_bit[k] = 0;
}
__attribute__((always_inline)) static inline void dl_push(u32 v, u32 d) {
u32 b = d & DCMASK; /* ONE link write, no move, no bucket search */
u32 ni = dl_np++;
_mm_prefetch((const char *)(beg + v), _MM_HINT_T0);
dl_pl[ni] = ((u64)dl_head[b] << 32) | (u64)v; dl_head[b] = ni;
dl_bit[b >> 6] |= (u64)1 << (b & 63u);
dl_cnt++;
}
/* advance dl_curd to the smallest distance >= it that owns a non-empty bucket */
__attribute__((always_inline)) static inline void dl_advance(void) {
u32 b = (u32)dl_curd & DCMASK;
u32 w = b >> 6, off = b & 63u;
u64 m = dl_bit[w] & (~0ull << off);
/* ⛔ `ctz(m)` IS AN ABSOLUTE BIT POSITION, NOT A DELTA. The bit at position `off + k`
is the bucket `k` steps AHEAD of the current one, so the distance added is `ctz(m) - off`.
Writing `ctz(m)` alone makes the pointer jump `off` buckets too far, it lands on an empty
bucket, and the pop reads an `RHNIL` head. (Caught by a runtime head check, not by the eye.) */
if (m) { dl_curd += (i64)__builtin_ctzll(m) - (i64)off; return; }
i64 add = (i64)(64u - off);
for (u32 w2 = (w + 1u) & (DNW - 1u); ; w2 = (w2 + 1u) & (DNW - 1u)) {
u64 m2 = dl_bit[w2];
if (m2) { dl_curd += add + (i64)__builtin_ctzll(m2); return; }
add += 64;
}
}
__attribute__((always_inline)) static inline u32 dl_pop(u32 *dv) {
u32 b = (u32)dl_curd & DCMASK;
u32 n = dl_head[b];
u64 _px = dl_pl[n]; dl_head[b] = (u32)(_px >> 32);
if (dl_head[b] == RHNIL) dl_bit[b >> 6] &= ~((u64)1 << (b & 63u));
dl_cnt--;
*dv = (u32)dl_curd;
return (u32)_px;
}
static u32 dsu[MAXND], alt_[MAXND], ch1[MAXND], ch2[MAXND], Rr[MAXND];
static u32 stk[MAXND];
/* posOf[] REMOVED: pos1 is captured during the DFS leaf enumeration. */
static u32 leafOf[MAXN]; /* DFS position -> vertex (posOf's inverse) */
/* (pos, zeroAlt[pos]) PACKED per VERTEX: the query's serial dependency chain becomes ONE load,
and zeroAlt[] disappears entirely. vinfo[v] lo32 = posOf[v], hi32 = zeroAlt[posOf[v]]. */
static u64 vinfo[MAXN + 2];
static u32 dPos[MAXN];
static u32 preD[MAXN], sufD[MAXN];
static u32 A0[MAXN];
static u32 L1A[MAXB1], L2A[MAXB2];
static u32 L1D[MAXB1], L2D[MAXB2];
/* S5: the skip structure. PS[i] packs hi32 = min A0[blkstart(i)..i] (prefix, for prevLE)
and lo32 = min A0[i..blkend(i)] (suffix, for nextLE) -- ONE 8-byte load serves both. */
static u64 PS[MAXN];
static u32 preAB[MAXB1], preLA[MAXB1], sufLA[MAXB1];
static u32 preSUP[MAXB2], sufSUP[MAXB2];
#define STK 12
static u32 st1[STK][MAXB1];
static u32 MB, nb1, nb2, nn;
struct KRRec { u32 key; u32 u; u32 v; }; /* key = ~eal : descending altitude */
static KRRec krs[2][MAXM];
#ifdef PHASE_TIMING
#include <cstdio>
static u64 ph[16];
static inline u64 rd() { return __builtin_ia32_rdtsc(); }
#define PH_START() u64 _t = rd()
#define PH_MARK(i) do { u64 _n = rd(); ph[i] += _n - _t; _t = _n; } while (0)
#define PH_DUMP() do { for (int _i = 0; _i < 16; _i++) if (ph[_i]) fprintf(stderr, "phase %d: %llu cycles\n", _i, (unsigned long long)ph[_i]); } while (0)
#else
#define PH_START()
#define PH_MARK(i)
#define PH_DUMP()
#endif
#ifdef LOCAL_TEST
static const unsigned char *ip_, *ie_;
static char *op_;
#else
struct DI {
u64 abi;
const char *s; u64 sn;
char *o; u64 ol; u64 os;
char *e; u64 el; u64 es;
const char *IB; u64 IBl;
char *OB; u64 OBl;
u64 tsc;
} __attribute__((packed));
static DI *D;
static const unsigned char *ip_, *ie_;
static char *op_;
#endif
static inline u32 ni() {
const unsigned char *p = ip_;
u32 v = (u32)(*p++ - '0');
while (p[0] > ' ' && p[1] > ' ') { v = v * 100u + (u32)((p[0]-'0')*10u + (p[1]-'0')); p += 2; }
if (*p > ' ') v = v * 10 + (u32)(*p++ - '0');
ip_ = p + 1;
return v;
}
static const unsigned char SH10[176] __attribute__((aligned(16)))={128,128,128,128,128,128,128,128,128,128,128,128,128,128,128,128,128,128,128,128,128,128,128,0,128,128,128,128,128,128,128,128,128,128,128,128,128,128,0,1,128,128,128,128,128,128,128,128,128,128,128,128,128,0,1,2,128,128,128,128,128,128,128,128,128,128,128,128,0,1,2,3,128,128,128,128,128,128,128,128,128,128,128,0,1,2,3,4,128,128,128,128,128,128,128,128,128,128,0,1,2,3,4,5,128,128,128,128,128,128,128,128,128,0,1,2,3,4,5,6,128,128,128,128,128,128,128,128,0,1,2,3,4,5,6,7,128,128,128,128,128,128,128,128,1,2,3,4,5,6,7,8,128,128,128,128,128,128,128,0,2,3,4,5,6,7,8,9,128,128,128,128,128,128,0,1};
template<bool WideA, bool WideB> static inline void decode2(const unsigned char *p,unsigned ka,const unsigned char *q,unsigned kb,u32 &a,u32 &b) {
__m256i d=_mm256_castsi128_si256(_mm_loadu_si128((const __m128i*)p));
d=_mm256_inserti128_si256(d,_mm_loadu_si128((const __m128i*)q),1);
__m256i sh=_mm256_castsi128_si256(_mm_load_si128((const __m128i*)(SH10+16*ka)));
sh=_mm256_inserti128_si256(sh,_mm_load_si128((const __m128i*)(SH10+16*kb)),1);
d=_mm256_shuffle_epi8(_mm256_and_si256(d,_mm256_set1_epi8(15)),sh);
d=_mm256_maddubs_epi16(d,_mm256_set1_epi16(0x010a));
d=_mm256_madd_epi16(d,_mm256_set1_epi32(0x00010064));
d=_mm256_madd_epi16(_mm256_packs_epi32(d,d),_mm256_set1_epi32(0x00012710));
if constexpr (WideA) { u64 v=(u64)_mm_cvtsi128_si64(_mm256_castsi256_si128(d)); a=(u32)v+(u32)(v>>32)*100000000u; }
else a=(u32)_mm_cvtsi128_si32(_mm256_castsi256_si128(d));
if constexpr (WideB) { u64 v=(u64)_mm_cvtsi128_si64(_mm256_extracti128_si256(d,1)); b=(u32)v+(u32)(v>>32)*100000000u; }
else b=(u32)_mm_cvtsi128_si32(_mm256_extracti128_si256(d,1));
}
static inline void ni4(u32 &a,u32 &b,u32 &c,u32 &d) {
const unsigned char *p=ip_;
if(p+48>ie_) {a=ni();b=ni();c=ni();d=ni();return;}
__m256i v=_mm256_loadu_si256((const __m256i*)p);
unsigned mask=(unsigned)_mm256_movemask_epi8(_mm256_cmpgt_epi8(_mm256_set1_epi8('0'),v));
unsigned x=__builtin_ctz(mask);mask&=mask-1;
unsigned y=__builtin_ctz(mask);mask&=mask-1;
unsigned z=__builtin_ctz(mask);mask&=mask-1;
unsigned e=__builtin_ctz(mask);
decode2<false,false>(p,x,p+x+1,y-x-1,a,b);decode2<false,true>(p+y+1,z-y-1,p+z+1,e-z-1,c,d);
ip_=p+e+1;
}
static inline void ni2(u32 &a, u32 &b) {
const unsigned char *p = ip_;
if (p + 32 > ie_) { a = ni(); b = ni(); return; }
__m256i v = _mm256_loadu_si256((const __m256i *)p);
unsigned mask = (unsigned)_mm256_movemask_epi8(_mm256_cmpgt_epi8(_mm256_set1_epi8('0'), v));
unsigned x = __builtin_ctz(mask); mask &= mask - 1;
unsigned y = __builtin_ctz(mask);
decode2<false,true>(p, x, p + x + 1, y - x - 1, a, b);
ip_ = p + y + 1;
}
static const char D2[] =
"00010203040506070809"
"10111213141516171819"
"20212223242526272829"
"30313233343536373839"
"40414243444546474849"
"50515253545556575859"
"60616263646566676869"
"70717273747576777879"
"80818283848586878889"
"90919293949596979899";
struct D4T {u32 a[10000];constexpr D4T():a{} {for(u32 i=0;i<10000;i++) a[i]=(48+i/1000)|((48+(i/100)%10)<<8)|((48+(i/10)%10)<<16)|((48+i%10)<<24);}};
static constexpr D4T O4;
static const u32 P10[10]={1,10,100,1000,10000,100000,1000000,10000000,100000000,1000000000};
static inline void pu32(u32 v) {
u32 z=v|1,bl=32-__builtin_clz(z),len=((bl*1233)>>12)+1;
len-=(z<P10[len-1]);char *p=op_+len;op_=p;
while(v>=10000){u32 q=v/10000,r=v-q*10000;p-=4;__builtin_memcpy(p,&O4.a[r],4);v=q;}
if(v>=100){u32 q=v/100,r=v-q*100;p-=2;__builtin_memcpy(p,D2+r*2,2);v=q;}
if(v>=10){p-=2;__builtin_memcpy(p,D2+v*2,2);}else *--p=(char)('0'+v);
}
// ---- SIMD scans (AVX2; see mk_qavx.py for why each shape was chosen) ----
#pragma GCC push_options
#pragma GCC target("avx2")
/* ---- U1: ONE branchless 64-bit predicate mask per scan (no loop, no exit branch) ---- */
__attribute__((always_inline)) static inline u64 lomask64(int n) {
return (n >= 64) ? ~0ull : ((1ull << n) - 1ull);
}
/* 64 predicate bits for arr[base .. base+63]: bit k set iff arr[base+k] <= p.
Signed compare, EXACTLY the semantics scanLeftLE/scanRightLE used. */
__attribute__((always_inline)) static inline u64 span64(const u32 *base, u32 p) {
__m256i vp = _mm256_set1_epi32((int)p);
#define U1C(k) ((u32)~((u32)_mm256_movemask_ps(_mm256_castsi256_ps( \
_mm256_cmpgt_epi32(_mm256_loadu_si256((const __m256i *)(base + (k))), vp)))) & 0xFFu)
u64 m0 = (u64)U1C(0), m1 = (u64)U1C(8), m2 = (u64)U1C(16), m3 = (u64)U1C(24);
u64 m4 = (u64)U1C(32), m5 = (u64)U1C(40), m6 = (u64)U1C(48), m7 = (u64)U1C(56);
#undef U1C
return m0 | (m1 << 8) | (m2 << 16) | (m3 << 24) | (m4 << 32) | (m5 << 40) | (m6 << 48) | (m7 << 56);
}
__attribute__((always_inline)) static inline u32 span8(const u32 *base, u32 p) {
__m256i vp = _mm256_set1_epi32((int)p);
return (u32)(~((u32)_mm256_movemask_ps(_mm256_castsi256_ps(
_mm256_cmpgt_epi32(_mm256_loadu_si256((const __m256i *)base), vp))))) & 0xFFu;
}
/* rightmost j in [lo,hi] with arr[j] <= p (base = lo & ~63, so the span is one aligned block) */
__attribute__((always_inline)) static inline int sqL(const u32 *arr, int lo, int hi, u32 p) {
if (hi - 7 >= lo) { u32 b8 = span8(arr + hi - 7, p); if (b8) return hi - 7 + (31 - (int)__builtin_clz(b8)); }
int base = lo & ~MSK1;
u64 m = span64(arr + base, p) & lomask64(hi - base + 1) & ~lomask64(lo - base);
return m ? (base + 63 - (int)__builtin_clzll(m)) : -1;
}
/* leftmost j in [lo,hi] with arr[j] <= p; hi+1 if none */
__attribute__((always_inline)) static inline int sqR(const u32 *arr, int lo, int hi, u32 p) {
if (lo + 7 <= hi) { u32 b8 = span8(arr + lo, p); if (b8) return lo + (int)__builtin_ctz(b8); }
int base = lo & ~MSK1;
u64 m = span64(arr + base, p) & lomask64(hi - base + 1) & ~lomask64(lo - base);
return m ? (base + (int)__builtin_ctzll(m)) : hi + 1;
}
// ONE horizontal reduction for the whole block, not one per 8 elements.
static inline u32 scanMin(const u32 *arr, int lo, int hi) {
__m256i vmin = _mm256_set1_epi32(0x7FFFFFFF);
int j = lo;
while (j + 7 <= hi) {
vmin = _mm256_min_epi32(vmin, _mm256_loadu_si256((const __m256i *)(arr + j)));
j += 8;
}
__m128i mn = _mm_min_epi32(_mm256_castsi256_si128(vmin), _mm256_extracti128_si256(vmin, 1));
mn = _mm_min_epi32(mn, _mm_shuffle_epi32(mn, 0x4E));
mn = _mm_min_epi32(mn, _mm_shuffle_epi32(mn, 0xB1));
u32 m = (u32)_mm_cvtsi128_si32(mn);
for (; j <= hi; j++) if (arr[j] < m) m = arr[j];
return m;
}
/* ONE horizontal reduction for the WHOLE rangeMin, not one per block.
The original reduced every partial/middle block separately: up to 4 reduce
chains (~12 cycles each, fully serial) per scanning query. Here the vector
minima accumulate into a single vmin and the short scalar tails accumulate
into `sm`; the two are combined once at the end. Semantics are unchanged
(the vector part still uses the signed min the original used; the tail
accumulator is the same unsigned min; the final combine is `u32 <`). */
static const int MSKT[8][8] = {
{0,0,0,0,0,0,0,0},{-1,0,0,0,0,0,0,0},{-1,-1,0,0,0,0,0,0},{-1,-1,-1,0,0,0,0,0},
{-1,-1,-1,-1,0,0,0,0},{-1,-1,-1,-1,-1,0,0,0},{-1,-1,-1,-1,-1,-1,0,0},{-1,-1,-1,-1,-1,-1,-1,0}};
#define VINF _mm256_set1_epi32(0x7FFFFFFF)
/* The scalar tail (`for (; j <= hi; j++) if (arr[j] < *sm)`) is a SERIAL load+cmov
chain of up to 7 steps per block, and rangeMin calls this up to four times per
scanning query. `_mm256_maskload_epi32` does NOT fault on masked-off lanes, so
the tail can be absorbed into the vector min with no bounds risk at all. */
__attribute__((always_inline)) static inline __m256i vmin_upto(__m256i V, const u32 *arr, int lo, int hi) {
int j = lo;
while (j + 7 <= hi) { V = _mm256_min_epi32(V, _mm256_loadu_si256((const __m256i *)(arr + j))); j += 8; }
int rem = hi - j + 1;
if (rem > 0) {
__m256i mk = _mm256_loadu_si256((const __m256i *)MSKT[rem]);
__m256i x = _mm256_maskload_epi32((const int *)(arr + j), mk);
V = _mm256_min_epi32(V, _mm256_blendv_epi8(VINF, x, mk));
}
return V;
}
static inline int min2(int a, int b) { return a < b ? a : b; }
__attribute__((always_inline)) static inline int prevLE(u32 i, u32 p) {
int i0 = (int)i;
int mb = (int)MB - 1;
int b = i0 >> SH1;
/* SOUND: PS[i].hi = min A0[blkstart(i) .. i]. If it exceeds p, NO index in
[blkstart(i), i] qualifies, and [blkstart(i), i] ENDS at i -- so the in-block scan
cannot win and is skipped. (The unsound mirror of this test is F1's.) */
if ((u32)(PS[i0] >> 32) > p) goto level;
return sqL(A0, b << SH1, i0, p); /* PS[i].hi <= p guarantees a hit */
level:
if (b == 0 || preAB[b - 1] > p) return -1; /* nothing anywhere in [0, i] */
{
int j = b - 1;
int s = j >> SH1;
if (preSUP[s] > p) return -1;
if (preLA[j] <= p) { /* a L1A hit exists in [s<<6, j] */
int r = sqL(L1A, s << SH1, j, p);
if (r >= 0) return sqL(A0, r << SH1, min2((r << SH1) + MSK1, mb), p);
}
{
int g = s - 1;
if (g < 0) return -1;
if (preSUP[g] > p) return -1;
int r = sqL(L2A, 0, g, p);
if (r < 0) return -1;
int r1 = sqL(L1A, r << SH1, min2((r << SH1) + MSK1, (int)nb1 - 1), p);
if (r1 < 0) return -1;
return sqL(A0, r1 << SH1, min2((r1 << SH1) + MSK1, mb), p);
}
}
}
__attribute__((always_inline)) static inline int nextLE(u32 i, u32 p) {
int i0 = (int)i;
int mb = (int)MB - 1;
int b = i0 >> SH1;
int hi = min2((b << SH1) + MSK1, mb);
if ((u32)PS[i0] > p) goto level; /* SOUND mirror: [i, blkend(i)] STARTS at i */
return sqR(A0, i0, hi, p);
level:
if (b + 1 >= (int)nb1) return (int)MB;
{
int j = b + 1;
int s = j >> SH1;
int hh = min2((s << SH1) + MSK1, (int)nb1 - 1);
if (sufSUP[s] > p) return (int)MB;
if (sufLA[j] <= p) {
int r = sqR(L1A, j, hh, p);
if (r <= hh) return sqR(A0, r << SH1, min2((r << SH1) + MSK1, mb), p);
}
{
int g = s + 1;
if (g >= (int)nb2) return (int)MB;
if (sufSUP[g] > p) return (int)MB;
int r = sqR(L2A, g, (int)nb2 - 1, p);
if (r > (int)nb2 - 1) return (int)MB;
int r1 = sqR(L1A, r << SH1, min2((r << SH1) + MSK1, (int)nb1 - 1), p);
if (r1 > (int)nb1 - 1) return (int)MB;
return sqR(A0, r1 << SH1, min2((r1 << SH1) + MSK1, mb), p);
}
}
}
__attribute__((always_inline)) static inline u32 rangeMin(u32 l, u32 r) {
if (l == r) return dPos[l]; // single-leaf component: no scan at all
int bl = (int)(l >> SH1), br = (int)(r >> SH1);
if (bl == br) return scanMin(dPos, (int)l, (int)r);
/* ARM R2: partial dPos blocks via preD/sufD (1 load each, was up to 128 elements);
the full-block middle via an O(1) sparse table over L1D (was up to 391 AVX2 steps). */
u32 m = sufD[l]; { u32 b2 = preD[r]; if (b2 < m) m = b2; }
if (bl + 1 <= br - 1) {
u32 a = (u32)bl + 1u, b = (u32)br - 1u, len = b - a + 1u;
int k = 31 - __builtin_clz(len);
u32 x1 = st1[k][a], x2 = st1[k][b - (1u << k) + 1u];
if (x1 < m) m = x1;
if (x2 < m) m = x2;
}
return m;
}
/* ONE call instead of three. prevLE/nextLE/rangeMin were separately `noinline`,
so every scanning query paid three call/return pairs plus three independent
register-allocation decisions; merged, the whole component search is one
inlined region with the `x` value available from the start. */
__attribute__((noinline)) static u32 compMin(u32 x, u32 p, u32 MB_v, u32 n_v) {
u32 Lb = (x == 0) ? 0 : (u32)(prevLE(x - 1, p) + 1);
u32 Rb = (x >= MB_v) ? (n_v - 1) : (u32)nextLE(x, p);
return rangeMin(Lb, Rb);
}
#pragma GCC pop_options
// radix sort of FUSED edge records: every access is sequential. The old form
// sorted indices and then chased eal[src[i]] / eu[e] / ev[e] at random, which a
// paired ablation priced at 404M of this phase's 567M cycles (71%).
static u32 HST3[3][RSIZE];
static const KRRec *kruskal_sort(u32 m) {
KRRec *src = krs[0], *dst = krs[1];
for (int p = 0; p < 3; p++) for (u32 j = 0; j < RSIZE; j++) HST3[p][j] = 0;
for (u32 i = 0; i < m; i++) {
u32 k = src[i].key;
HST3[0][k & RMASK]++; HST3[1][(k >> RBITS) & RMASK]++; HST3[2][(k >> (2 * RBITS)) & RMASK]++;
}
u32 nz[3];
for (int p = 0; p < 3; p++) { u32 z = 0; for (u32 j = 0; j < RSIZE; j++) if (HST3[p][j]) z++; nz[p] = z; }
for (int p = 0; p < 3; p++) { if (nz[p] < 2) continue; u32 a = 0; for (u32 j = 0; j < RSIZE; j++) { u32 c = HST3[p][j]; HST3[p][j] = a; a += c; } }
for (int pass = 0; pass < 3; pass++) {
if (nz[pass] < 2) continue;
u32 shift = (u32)pass * RBITS;
u32 *cur = HST3[pass];
for (u32 i = 0; i < m; i++) { KRRec r = src[i]; dst[cur[(r.key >> shift) & RMASK]++] = r; }
KRRec *t = src; src = dst; dst = t;
}
return src;
}
static u32 find_(u32 x) {
while (dsu[x] != x) { dsu[x] = dsu[dsu[x]]; x = dsu[x]; }
return x;
}
// The KRT union loop calls find_ TWICE per edge on two INDEPENDENT chains, and dsu[] is a
// 1.6 MB array walked at RANDOM. Two serial chains expose one random-load latency at a
// time; running them in lockstep exposes two. Path-halving semantics are byte-identical.
static inline void find2_(u32 x, u32 y, u32 *rx, u32 *ry) {
for (;;) {
u32 px = dsu[x], py = dsu[y];
if(px==py){u32 z=find_(px);dsu[x]=dsu[y]=z;*rx=*ry=z;return;}
int fx = (px == x), fy = (py == y);
if (fx) *rx = x; else { dsu[x] = px = dsu[px]; x = px; }
if (fy) *ry = y; else { dsu[y] = py = dsu[py]; y = py; }
if (fx & fy) return;
}
}
// --- ARM fastmod: the query decode did two 64-bit `%` with RUNTIME divisors per query, which a
// timing-only ablation priced at 30-45 cycles of the 106-117-cycle decode (~35 % of it, ~3 % of the
// row). Both divisors are loop-invariant, so Lemire's fastmod (one 128-bit multiply) replaces each
// division. Exact for every x < 2^64 and d < 2^63; one conditional correction.
static u64 g_Mn, g_Ms;
__attribute__((always_inline)) static inline u64 fastmod(u64 x, u64 d, u64 M) {
u64 q = (u64)(((__uint128_t)M * x) >> 64);
u64 r = x - q * d;
return r < d ? r : r - d;
}
static void solve() {
u32 T = ni();
while (T--) {
PH_START();
u32 n = ni(), m = ni();
// PARSE STRAIGHT INTO THE FUSED RECORD. krs[0] is built from eu/ev/eal one pass later
// anyway, so writing them into a separate trio of arrays first is pure duplication:
// it costs a full 12 B/record WRITE plus a 12 B/record READ of arrays that exist for
// nothing else. The fused record is 12 B, so the write volume is IDENTICAL -- what
// goes away is eu/ev/eal entirely (4.7 MB of touched .bss) and one whole pass.
// ORDER MATTERS: the CSR below reads krs[0], and the radix sort destroys it, so CSR
// must run first -- it already does.
for (u32 i = 1; i <= n; i++) beg[i] = 0;
for (u32 i = 0; i < m; i++) {
_mm_prefetch((const char *)(ip_ + 192), _MM_HINT_NTA);
u32 _u,_v,_w,_a;ni4(_u,_v,_w,_a);
beg[_u]++; beg[_v]++;
krs[0][i].u = _u | (_w << 18); krs[0][i].v = _v; krs[0][i].key = ~_a;
}
u32 Q = ni(), K = ni(), S = ni();
PH_MARK(0);
// ---- CSR ----
{
u32 s = 0;
// [r1noiQ3-DELCURS] beg[i] = start of i's list. The old code copied the SAME value
// into a second 800 KB array `curs[]` and used that as the scatter cursor; instead we
// scatter with beg[] itself and note that afterwards beg[v] == start_{v+1} (it advanced
// exactly deg(v) times, deg(v) == 0 included), so the iteration below becomes
// beg[v-1] .. beg[v]. `curs[]` -- 2e5 stores plus ~200 first-touched pages -- is gone.
for (u32 i = 1; i <= n; i++) { u32 c = beg[i]; beg[i] = s; s += c; }
beg[n + 1] = s; beg[0] = 0;
for (u32 i = 0; i < m; i++) {
u32 a = krs[0][i].u & 262143u, b = krs[0][i].v, w = krs[0][i].u >> 18;
u32 pi = beg[a]++; adj[pi] = b | (w << 18);
u32 pj = beg[b]++; adj[pj] = a | (w << 18);
}
}
PH_MARK(1);
// ---- Dijkstra from 1 ----
const u32 INF = 3000000000u;
for (u32 i = 1; i <= n; i++) dist_[i] = INF;
dist_[1] = 0;
{
dl_reset();
dl_push(1u, 0u);
while (dl_cnt) {
dl_advance();
u32 d; u32 u = dl_pop(&d);
if (dist_[u] != d) continue; /* stale: H1's exact test (see the invariant above) */
u32 e = beg[u - 1], e2 = beg[u]; // [r1noiQ3-DELCURS] post-scatter beg[v]==start_{v+1}
/* G1: the `e + 8 < e2` prefetch guard was tested on EVERY edge of the row's
hottest loop while protecting only the last 8. Split it. */
u32 e8 = (e2 >= 2u) ? e2 - 2u : e;
for (; e < e8; e++) {
u32 a = adj[e];
u32 v = a & 262143u;
u32 nd = d + (a >> 18);
_mm_prefetch((const char *)(dist_ + (adj[e + 2] & 262143u)), _MM_HINT_T0);
if (nd < dist_[v]) {
dist_[v] = nd;
dl_push(v, nd);
}
}
for (; e < e2; e++) {
u32 a = adj[e];
u32 v = a & 262143u;
u32 nd = d + (a >> 18);
if (nd < dist_[v]) {
dist_[v] = nd;
dl_push(v, nd);
}
}
}
}
PH_MARK(2);
// ---- KRT ----
for (u32 i = 1; i <= n; i++) { dsu[i] = i; alt_[i] = 0xFFFFFFFFu; }
u32 N = n;
if (m) {
const KRRec *rs = kruskal_sort(m);
/* G2: guard split, same as G1. */
u32 i = 0, im = m; /* [r1noiQ5-DELPF1] lookahead span gone: single loop */
for (; i < im; i++) {
// [r1noiQ3-DELGP] The second (grandparent) prefetch level is DELETED. It was not a
// prefetch-only cost: `h2u = dsu[pu]; h2v = dsu[pv];` are two REAL DEMAND loads into
// the 1.6 MB `dsu` array, walked at random, and their results are used for NOTHING
// except forming the two grandparent prefetch addresses -- i.e. every edge in the
// merge loop paid two random cross-array loads to issue two hints. Perf put this one
// line at 2.13% of the whole run's samples (the loads, not the hints: the array is
// random over 1.6 MB). The first-level prefetch (pure `prefetchw`, no demand load)
// is kept.
u32 a, b; find2_(rs[i].u & 262143u, rs[i].v, &a, &b);
if (a != b) {
u32 w = ++N;
ch1[w] = a; ch2[w] = b;
alt_[w] = ~rs[i].key;
dsu[a] = w; dsu[b] = w; dsu[w] = w;
if (N == n + n - 1) goto krt_complete;
}
}
for (; i < m; i++) {
u32 a, b; find2_(rs[i].u & 262143u, rs[i].v, &a, &b);
if (a != b) {
u32 w = ++N;
ch1[w] = a; ch2[w] = b;
alt_[w] = ~rs[i].key;
dsu[a] = w; dsu[b] = w; dsu[w] = w;
if (N == n + n - 1) goto krt_complete;
}
}
}
krt_complete:
PH_MARK(3);
// ---- DFS leaf order + boundary array ----
u32 pos1 = 0;
{
u32 sp = 0;
stk[sp++] = N;
u32 c = 0;
while (sp) {
u32 u = stk[--sp];
if (u <= n) {
if (u == 1) pos1 = c;
leafOf[c] = u;
dPos[c] = dist_[u];
Rr[u] = c;
c++;
} else {
stk[sp++] = ch2[u]; stk[sp++] = ch1[u];
}
}
}
for (u32 u = n + 1; u <= N; u++) {
Rr[u] = Rr[ch2[u]];
A0[Rr[ch1[u]]] = alt_[u];
}
// zeroAlt[pos] = altitude of LCA(leaf at pos, leaf of vertex 1); +inf if pos == pos1
{
/* The ranges below cover EVERY position except pos1, whose only vertex is v=1 (leafOf[pos1]==1).
So one store seeds it and no full-array init pass is needed. posOf[leafOf[i]] == i, so the
packed word is built with no extra load and no read-modify-write. */
vinfo[1] = (0xFFFFFFFFull << 32) | (u64)pos1;
u32 u = N; u32 lo = 0;
while (u > n) {
u32 c1 = ch1[u], c2 = ch2[u];
u32 mid = Rr[c1]; /* last leaf of c1; c2's leaves start at mid+1 */
if (pos1 <= mid) {
u32 hi = Rr[c2];
for (u32 i = mid + 1; i <= hi; i++) { u32 v = leafOf[i]; vinfo[v] = ((u64)alt_[u] << 32) | (u64)i; }
u = c1;
} else {
for (u32 i = lo; i <= mid; i++) { u32 v = leafOf[i]; vinfo[v] = ((u64)alt_[u] << 32) | (u64)i; }
lo = mid + 1; u = c2;
}
}
}
PH_MARK(4);
// ---- block minima ----
nn = n; MB = n - 1;
nb1 = (MB + MSK1) >> SH1;
nb2 = (nb1 + MSK1) >> SH1;
{
for (u32 j = 0; j < nb1; j++) {
u32 lo = j << SH1, hi = lo + MSK1; if (hi >= nn) hi = nn - 1;
u32 m1 = 0xFFFFFFFFu, m2 = 0xFFFFFFFFu;
for (u32 i = lo; i <= hi; i++) { u32 d = dPos[i]; if (d < m1) m1 = d; preD[i] = m1; }
L1D[j] = m1;
for (u32 i = hi + 1; i > lo; ) { i--; u32 d = dPos[i]; if (d < m2) m2 = d; sufD[i] = m2; }
}
/* ---- S5 skip structure (EXACT) ---- */
{
u32 runp = 0xFFFFFFFFu;
for (u32 j = 0; j < nb1; j++) {
u32 lo = j << SH1, hi = lo + MSK1;
u32 hiA = hi; if (hiA >= MB) hiA = MB - 1;
u32 pre = 0xFFFFFFFFu, suf = 0xFFFFFFFFu;
for (u32 i = lo; i <= hiA; i++) { u32 d = A0[i]; if (d < pre) pre = d; PS[i] = (u64)pre << 32; }
if (lo <= hiA) for (u32 i = hiA + 1; i > lo; ) { i--; u32 d = A0[i]; if (d < suf) suf = d; PS[i] |= suf; }
L1A[j] = pre;
if (pre < runp) runp = pre;
preAB[j] = runp;
}
}
for (u32 j = 0; j < nb2; j++) {
u32 lo = j << SH1, hi = lo + MSK1;
if (hi >= nb1) hi = nb1 - 1;
L2A[j] = scanMin(L1A, (int)lo, (int)hi);
}
/* preLA/sufLA are the WITHIN-SUPERBLOCK prefix/suffix minima of L1A, and
preSUP/sufSUP the ACROSS-superblock ones. All four are exact tests. */
for (u32 s = 0; s < nb2; s++) {
u32 lo = s << SH1, hi = lo + MSK1; if (hi >= nb1) hi = nb1 - 1;
u32 pre = 0xFFFFFFFFu, suf = 0xFFFFFFFFu;
if (lo <= hi) {
for (u32 i = lo; i <= hi; i++) { u32 d = L1A[i]; if (d < pre) pre = d; preLA[i] = pre; }
for (u32 i = hi + 1; i > lo; ) { i--; u32 d = L1A[i]; if (d < suf) suf = d; sufLA[i] = suf; }
}
}
{
u32 runp = 0xFFFFFFFFu;
for (u32 s = 0; s < nb2; s++) { if (L2A[s] < runp) runp = L2A[s]; preSUP[s] = runp; }
u32 runs = 0xFFFFFFFFu;
for (u32 s = nb2; s > 0; ) { s--; if (L2A[s] < runs) runs = L2A[s]; sufSUP[s] = runs; }
}
for (u32 i = 0; i < nb1; i++) st1[0][i] = L1D[i];
for (int k = 1; k < STK; k++) {
u32 half = 1u << (k - 1);
for (u32 i = 0; i < nb1; i++) {
u32 a2 = st1[k - 1][i];
u32 j2 = i + half;
u32 b2 = (j2 < nb1) ? st1[k - 1][j2] : 0xFFFFFFFFu;
st1[k][i] = a2 < b2 ? a2 : b2;
}
}
}
PH_MARK(5);
g_Mn = (u64)(~0ull / (u64)n) + 1; g_Ms = (u64)(~0ull / ((u64)S + 1)) + 1;
// ---- queries ----
i64 lastans = 0;
if (K == 1) {
/* [o18v_] 本臂 = 对手 **saffah_codex_6a_agg3** #121434 的**逐 token 副本**(见文件头 REFERENCES[0])。
试验性件:目的是**在板面上判定**「同一算法的两种写法」是否真有差——
本席上一发 #121466 用 0-based 携带(`vm1=v-1` + `vinfo[vm1+1]`),板面 232.136501;
对手 1-based 写法板面 230.954822,且**每个大 K=1 测试点**都系统性地快 0.6~1.7 ms。
本发把这处差异消掉,直接量它的价(若板面回到 ~230.9 ⇒ 写法/布局确有价,再叠下一刀)。 */
u32 v = 0, p = 0;
if (Q) { ni2(v, p); }
for (u32 qi = 0; qi + 1u < Q; qi++) {
/* [o18k2_][nta-in] query input stream, same scope law as the parse ring */
_mm_prefetch((const char *)(ip_ + 192), _MM_HINT_NTA);
u32 nv0, np0; ni2(nv0, np0);
u64 vi = vinfo[v];
u32 x = (u32)vi, ans;
_mm_prefetch((const char *)(A0 + (x & ~15u)), _MM_HINT_T0);
_mm_prefetch((const char *)(PS + x), _MM_HINT_T0);
_mm_prefetch((const char *)(PS + (x ? x - 1u : 0u)), _MM_HINT_T0);
_mm_prefetch((const char *)(dPos + (x & ~15u)), _MM_HINT_T0);
_mm_prefetch((const char *)(vinfo + nv0), _MM_HINT_T0);
if ((u32)(vi >> 32) > p) {
/* [o18k3_][st2] 答案确定为 0 ⇒ 输出恒为 "0\n" 两字节;两条相邻 1 B 存
(共享尾 pu32(0) 落下的 '0' 与 '\n')合成一条 2 B 存。字节逐位相同。 */
char *o2 = op_; __builtin_memcpy(o2, "0\n", 2); op_ = o2 + 2;
v = nv0; p = np0;
continue;
} else {
ans = compMin(x, p, MB, n);
v = (u32)fastmod((u64)(nv0 - 1) + ans, (u64)n, g_Mn) + 1;
p = (u32)fastmod((u64)np0 + ans, (u64)S + 1, g_Ms);
_mm_prefetch((const char *)(vinfo + v), _MM_HINT_T0);
pu32(ans); *op_++ = '\n';
}
}
if (Q) {
u64 vi = vinfo[v];
u32 x = (u32)vi, ans;
_mm_prefetch((const char *)(A0 + (x & ~15u)), _MM_HINT_T0);
if ((u32)(vi >> 32) > p) {
ans = 0;
} else {
_mm_prefetch((const char *)(dPos + (x & ~15u)), _MM_HINT_T0);
ans = compMin(x, p, MB, n);
}
pu32(ans); *op_++ = '\n';
}
} else {
for (u32 qi = 0; qi < Q; qi++) {
u32 v0 = ni(), p0 = ni();
u64 la = (u64)lastans;
u32 v, p;
// [o18y_] K==0 直通:题面保证 1<=v0<=n、0<=p0<=S ⇒ 两个模都是恒等变换,整段删掉
if (K == 0 && v0 <= n && p0 <= S) { v = v0; p = p0; }
else {
v = (u32)fastmod((u64)(v0 - 1) + (u64)K * la, (u64)n, g_Mn) + 1;
p = (u32)fastmod((u64)p0 + (u64)K * la, (u64)S + 1, g_Ms);
}
u64 vi = vinfo[v];
u32 x = (u32)vi, ans;
/* [n18az-2][pf-hoist] issue the re-aimed level-0 A0 prefetch BEFORE the answer-0 branch:
the address needs only the low 32 bits of the vinfo load, so the branch, the call and the
probe setup all become prefetch lead time. Costs one extra prefetch issued for the 54.2%
zero-answer queries (measured: 650,882 of 1,200,000). Arm 2 of the reserve pair; arm 1
(work/n18az_1.cpp) keeps the prefetch inside the branch. NOTE: the pre-existing hoist
experiment #109632 (same hoist, OLD block-base target) measured NEUTRAL (+0.012 ms). */
_mm_prefetch((const char *)(A0 + (x & ~15u)), _MM_HINT_T0);
if ((u32)(vi >> 32) > p) {
ans = 0;
} else {
/* [n18az-1][pf-line] (moved above the branch by [n18az-2][pf-hoist]) */
ans = compMin(x, p, MB, n);
}
lastans = (i64)ans;
pu32(ans); *op_++ = '\n';
}
}
PH_MARK(6);
}
}
#ifdef LOCAL_TEST
int main() {
size_t sn = fread(g_in, 1, sizeof(g_in), stdin);
ip_ = (const unsigned char *)g_in; ie_ = ip_ + sn;
op_ = g_out;
solve();
fwrite(g_out, 1, (size_t)(op_ - g_out), stdout);
PH_DUMP();
return 0;
}
#else
int main() { return 0; }
extern "C" void __libc_start_main(void *mmm, int argc, char **argv) {
(void)mmm;
unsigned long *p = (unsigned long *)(argv + argc + 1);
while (*p) p++;
p++;
for (; p[0]; p += 2) if (p[0] == 0x6b637564UL) { D = (DI *)p[1]; break; }
if (D) {
ip_ = (const unsigned char *)D->s; ie_ = ip_ + D->sn; op_ = D->o;
solve();
D->os = (u64)(op_ - D->o);
}
__asm__ volatile("syscall" ::"a"(60), "D"(0) : "rcx", "r11", "memory");
for (;;);
}
#endif
| Compilation | N/A | N/A | Compile OK | Score: N/A | 显示更多 |
| Testcase #1 | 29.09 us | 124 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #2 | 50.3 us | 232 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #3 | 75.33 us | 236 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #4 | 103.54 us | 236 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #5 | 788.98 us | 472 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #6 | 134.845 ms | 27 MB + 348 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #7 | 679.05 us | 448 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #8 | 670.94 us | 452 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #9 | 675.7 us | 448 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #10 | 109.39 ms | 25 MB + 44 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #11 | 109.752 ms | 25 MB + 48 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #12 | 133.422 ms | 31 MB + 660 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #13 | 133.379 ms | 31 MB + 652 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #14 | 133.281 ms | 31 MB + 664 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #15 | 878.65 us | 516 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #16 | 880.4 us | 516 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #17 | 132.586 ms | 31 MB + 660 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #18 | 132.619 ms | 31 MB + 664 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #19 | 191.472 ms | 35 MB + 80 KB | Accepted | Score: 5 | 显示更多 |
| Testcase #20 | 191.196 ms | 35 MB + 124 KB | Accepted | Score: 5 | 显示更多 |