代码

#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
#define rep(i, j, k) for(int i = (j); i <= (k); i++)
#define per(i, j, k) for(int i = (j); i >= (k); i--)
#define pb emplace_back
#define fi first
#define se second
using vi = vector<int>;
using pi = pair<int, int>;

template<typename T0, typename T1> bool chmin(T0 &x, const T1 &y){
	if(y < x){x = y; return true;} return false;
}
template<typename T0, typename T1> bool chmax(T0 &x, const T1 &y){
	if(x < y){x = y; return true;} return false;
}

template<typename T> void debug(char *s, T x){
	cerr << s <<" = "<< x <<endl;
}
template<typename T, typename ...Ar> void debug(char *s, T x, Ar... y){
	int dep = 0;
	while(!(*s == ',' && dep == 0)){
		if(*s == '(') dep++;
		if(*s == ')') dep--;
		cerr << *s++;
	}
	cerr <<" = "<< x <<",";
	debug(s + 1, y...);
}
#define gdb(...) debug((char*)#__VA_ARGS__, __VA_ARGS__)

using u32 = uint32_t;
using u64 = uint64_t;
constexpr int mod = 998244353;
struct mint{
	u32 x;
	
	mint(): x(0){}
	mint(int _x){
		_x %= mod;
		if(_x < 0) _x += mod;
		x = _x;
	}

	u32 val()const {
		return x;
	}
	mint qpow(int y = mod - 2)const {
		assert(y >= 0);
		mint t = *this, res = 1;
		while(y){
			if(y%2) res *= t;
			t *= t;
			y /= 2;
		}
		return res;
	}

	mint& operator += (const mint &B){
		if((x += B.x) >= mod) x -= mod;
		return *this;
	}
	mint& operator -= (const mint &B){
		if((x -= B.x) >= mod) x += mod;
		return *this;
	}
	mint& operator *= (const mint &B){
		x = (u64)x * B.x % mod;
		return *this;
	}
	mint& operator /= (const mint &B){
		return *this *= B.qpow();
	}
	friend mint operator + (const mint &A, const mint &B){
		return mint(A) += B;
	}
	friend mint operator - (const mint &A, const mint &B){
		return mint(A) -= B;
	}
	friend mint operator * (const mint &A, const mint &B){
		return mint(A) *= B;
	}
	friend mint operator / (const mint &A, const mint &B){
		return mint(A) /= B;
	}
	mint operator - ()const {
		return mint() - *this;
	}
};

void sort(unsigned *a, int n){
	for(int i = 1; i < n; i += 2){
		(a[i] += a[i - 1]) >= mod? a[i] -= mod: 0;
	}
}

评测结果