这是什么愚蠢的问题啊QAQAQ第一次求组合数出错啊
请看主函数

#include <cstdlib>
#include <iostream>
#include <cstdio>
#include <math.h>
#include <cstring>
#include <time.h>
#include <complex>
#include <algorithm>
#include <queue>

#pragma warning(disable:4996)
#define lowbit(a) ((a)&-(a))

template<typename T> T min(T x, T y)
{
    return x < y ? x : y;
}
template<typename T> T max(T x, T y)
{
    return x > y ? x : y;
};

const long long P = 998244353;
const long long MAXN = 500005;

long long qpow(long long x, long long y)
{
	if(!y)
		return 1;
	long long t = qpow(x, y / 2);
	t = t*t % P;
	if(y & 1)
		t = t*x % P;
	return t;
}

long long N, len = 1;
long long fac[MAXN];

long long C(long long n, long long k)
{
	if(k > n)
		return 0;
	return fac[n] * qpow(fac[k], P - 2) % P * qpow(fac[n - k], P - 2) % P;
}

void init()
{
    N = 100005;
	fac[0] = 1;
	for(long long i = 1; i <= N; i++)
		fac[i] = fac[i - 1] * i % P;
}

int main()
{
	init();
	long long i = 44683;
	if(C(i, 2) != i * (i - 1) / 2)
	{
		printf("%lld %lld %lld\n", i, C(i, 2), i * (i - 1) / 2);
		printf("%lld %lld %lld\n", fac[i], fac[2], fac[i] * qpow(fac[i - 2], P - 2) % P * qpow(fac[2], P - 2) % P);
		system("pause");
	}
    
    return 0;
}