Submission #36721825

---

Source Code Expand

#include<bits/stdc++.h>
#define LL long long
#define MOD 1000000007
using namespace std;
int mul(const int &a, const int &b)
{
	return 1LL * a * b % MOD;
}
void Mul(int &a, const int &b)
{
	a = 1LL * a * b % MOD;
}
void Sqr(int &a)
{
	a = 1LL * a * a % MOD;
}
int qwqmi(int x, int k = MOD - 2)
{
	int res = 1;
	while(k)
	{
		if(k & 1) Mul(res, x);
		Sqr(x), k >>= 1;
	}
	return res;
}
const int N = 4e6 + 2005;
int fac[N], facinv[N];
void preprocess()
{
	fac[0] = facinv[0] = 1;
	for(int i = 1; i < N; ++i)
		fac[i] = mul(fac[i - 1], i);
	facinv[N - 1] = qwqmi(fac[N - 1]);
	for(int i = N - 2; i >= 1; --i)
		facinv[i] = mul(facinv[i + 1], i + 1);
}
int n, m, x, s;
int main()
{
	preprocess();
	scanf("%d %d", &n, &m);
	for(int i = 1; i <= n; ++i)
	{
		scanf("%d", &x);
		s += x;
	}
	if(s > m) puts("0");
	else if(s == m) puts("1");
	else
	{
		int res = facinv[s + n];
		for(int i = m - s + 1; i <= m + n; ++i)
			Mul(res, i % MOD);
		printf("%d\n", res);
	}
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:42:7: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   42 |  scanf("%d %d", &n, &m);
      |  ~~~~~^~~~~~~~~~~~~~~~~
./Main.cpp:45:8: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   45 |   scanf("%d", &x);
      |   ~~~~~^~~~~~~~~~

Judge Result