Submission #1228410

#	Time	Username	Problem	Language	Result	Execution time	Memory
1228410		_rain_	Asceticism (JOI18_asceticism)	C++20	49 / 100	31 ms	28232 KiB

asceticism

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;

const int N=(int)3000;
const int MOD=(int)1e9+7;
	int add(int a,int b){
		return a+b>=MOD?a+b-MOD:a+b;
	}
	int sub(int a,int b){
		return a-b<0?a-b+MOD:a-b;
	}
	int mul(int a,int b){
		return (LL)a*b%MOD;
	}
	
	int dp[N+2][N+2];
	int n,k;
	

int main(){
	ios::sync_with_stdio(false);
	cin.tie(0) ; cout.tie(0);
	#define task "main"
	if (fopen(task".inp","r")){
		freopen(task".inp","r",stdin);
		freopen(task".out","w",stdout);
	}
	cin>>n>>k;
	dp[1][1]=1;
	for(int i=2;i<=n;++i){
		for(int j=1;j<=i;++j){
			dp[i][j]=add(dp[i][j],mul(j,dp[i-1][j]));
			dp[i][j+1]=add(mul(i-j,dp[i-1][j]),dp[i][j+1]);
		}
	}

	cout<<dp[n][k];
	return 0;
}

Compilation message (stderr)

asceticism.cpp: In function 'int main()':
asceticism.cpp:26:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |                 freopen(task".inp","r",stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
asceticism.cpp:27:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |                 freopen(task".out","w",stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 20 / 20
• Subtask 3: 25 / 25
• Subtask 4: 0 / 51