代码

#include "router.h"
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <stddef.h>
#include <sys/auxv.h>

// ============================================================================
// router32 flat /16 fill table + per-slice 256-slot u8 deep table (L3-resident)
// + per-/24 256-slot u8 table for len>=25 (rare).
// Shallow query = one L2-resident 256KB u32 load. Deep = + one ~6MB L3 load.
// Build = single pass, pure fill (last write wins; input sorted by (addr,len)).
// ============================================================================

struct DuckInfo {
  uint64_t abi_version;
  const char *stdin_ptr; uint64_t stdin_size;
  char *stdout_ptr; uint64_t stdout_limit; uint64_t stdout_size;
  char *stderr_ptr; uint64_t stderr_limit; uint64_t stderr_size;
  const char *IB_ptr; uint64_t IB_limit;
  char *OB_ptr; uint64_t OB_limit;
  uint64_t tsc_frequency;
} __attribute__((packed));

#include "flat16_core.h"

static inline int u32dec(unsigned v, char *o){
    char tmp[16]; int n = 0;
    do { tmp[n++] = (char)('0' + (v % 10)); v /= 10; } while (v);
    for (int i = 0; i < n; i++) o[i] = tmp[n-1-i];
    return n;
}

extern "C" int __libc_start_main(int (*mf)(int,char**,char**), int argc, char** argv, void* p4, void* p5, void* p6){
    (void)mf;(void)argc;(void)argv;(void)p4;(void)p5;(void)p6;
    struct DuckInfo *D = (struct DuckInfo*)getauxval(0x6b637564);
    const unsigned char *p = (const unsigned char*)D->stdin_ptr;
    int n = *(const int*)p; p += 4;
    int q = *(const int*)p; p += 4;
    const RoutingTableEntry *a = (const RoutingTableEntry*)p;
    p += (size_t)n * 12;
    const unsigned *queries = (const unsigned*)p;

    init(n, q, a);

    unsigned checksum = 0;
    for (int i = 0; i < q; i++) {
        checksum ^= lookup(__builtin_bswap32(queries[i]));
    }

    char *o = D->stdout_ptr;
    int len = u32dec(checksum, o);
    o[len] = '\n';
    D->stdout_size = (uint64_t)len + 1;
    __asm__ volatile("mov $60,%eax; xor %edi,%edi; syscall");
    __builtin_unreachable();
}

评测结果