Submission #35717030

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Source Code Expand

#include<bits/stdc++.h>
#define LL long long
#define MOD 998244353
using namespace std;
int inc(const int &a, const int &b)
{
	return a + b >= MOD ? a + b - MOD : a + b;
}
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 inv2 = qwqmi(2);
int binom2(int x)
{
	return mul(mul(x, x - 1), inv2);
}
const int N = 5e3 + 5;
int n, r[N], c[N], sum, _sum, x0;
int f[N][N];
int main()
{
	scanf("%d", &n);
	for(int i = 1; i <= n; ++i) 
		scanf("%d", &r[i]), _sum += r[i];
	for(int i = 1; i <= n; ++i) 
	{
		scanf("%d", &c[i]);
		sum += c[i];
		if(c[i] == 2) ++x0;
	}
	if(sum != _sum)
	{
		puts("0");
		return 0;
	}
	f[0][x0] = 1;
	for(int i = 1; i <= n; ++i)
	{
		sum -= r[i];
		for(int x = 0; x <= n; ++x)
		{
			int y = sum - 2 * x;
			if(r[i] == 0) f[i][x] = f[i - 1][x];
			if(r[i] == 1) f[i][x] = inc(mul(f[i - 1][x], y + 1), mul(f[i - 1][x + 1], x + 1));
			if(r[i] == 2) f[i][x] = inc(inc(mul(f[i - 1][x + 1], x + 1), mul(f[i - 1][x + 1], mul(x + 1, y))), 
										inc(mul(f[i - 1][x + 2], binom2(x + 2)), mul(f[i - 1][x], binom2(y + 2))));
		}
	}
	printf("%d\n", f[n][0]);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:41:7: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   41 |  scanf("%d", &n);
      |  ~~~~~^~~~~~~~~~
./Main.cpp:43:8: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   43 |   scanf("%d", &r[i]), _sum += r[i];
      |   ~~~~~^~~~~~~~~~~~~
./Main.cpp:46:8: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   46 |   scanf("%d", &c[i]);
      |   ~~~~~^~~~~~~~~~~~~

Judge Result