Submission #57035

#	Time	Username	Problem	Language	Result	Execution time	Memory
57035		cki86201	Tents (JOI18_tents)	C++11	100 / 100	127 ms	72000 KiB

tents

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>
#include <math.h>
#include <assert.h>
#include <queue>
#include <map>
#include <set>
#include <string>
#include <algorithm>
#include <iostream>
#include <functional>
#include <unordered_map>

using namespace std;
typedef pair<int, int> Pi;
typedef long long ll;
#define Fi first
#define Se second
#define pb(x) push_back(x)
#define sz(x) (int)x.size()
#define rep(i, n) for(int i=0;i<n;i++)
#define all(x) x.begin(), x.end()

const int MOD = 1e9 + 7;
ll d[3030][3030];

void solve(){
	int n, m; scanf("%d%d", &n, &m);
	rep(i, 3030) d[i][0] = d[0][i] = 1;
	for(int i=1;i<=n;i++) {
		for(int j=1;j<=m;j++) {
			d[i][j] = d[i-1][j] + 4LL * d[i-1][j-1] * j;
			if(j >= 2) d[i][j] += j * (j-1) / 2 * d[i-1][j-2];
			if(i >= 2) d[i][j] += j * (i-1) * d[i-2][j-1];
			d[i][j] %= MOD;
		}
	}
	printf("%lld\n", (d[n][m] + MOD - 1) % MOD);
}

int main(){
	int Tc = 1; //scanf("%d", &Tc);
	for(int tc=1;tc<=Tc;tc++){
		solve();
	}
	return 0;
}

Compilation message (stderr)

tents.cpp: In function 'void solve()':
tents.cpp:30:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  int n, m; scanf("%d%d", &n, &m);
            ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 48 / 48
• Subtask 2: 52 / 52