Submission #1349717

#	Time	Username	Problem	Language	Result	Execution time	Memory
1349717		jump	Tents (JOI18_tents)	C++20	Compilation error	0 ms	0 KiB

tents

#include <bits/stdc++.h>
#define int long long
int dp[3010][3010];
int pref[3010][3010];
int pref2[3010][3010];
int n,m;
int MOD=1e9+7;
int c2(int a){
	return (a*(a-1))/2;
}
signed main() {
	std::cin >> n >> m;
	int sum=0;
	for(int i=0;i<=n+1;i++)pref[i][0]=1,pref[i][1]=1;
	for(int j=0;j<=m+1;j++)pref[0][j]=pref[1][j]=j*4+1+c2(j);
	pref[0][0]=1;
	pref[0][1]=1;
	pref[1][0]=1;
	pref[1][1]=1;
	for(int i=2;i<=n;i++){
		for(int j=2;j<=m;j++){
			pref[i][j]=(pref[i-1][j]+pref[i-1][j-1]*j*4+pref[i-1][j-2]*C2(j)+pref[i-2][j-1]*(i-1)*j)%MOD;
		}
	}
	std::cout << pref[n][m]-1;
}

Compilation message (stderr)

tents.cpp: In function 'int main()':
tents.cpp:22:84: error: 'C2' was not declared in this scope; did you mean 'c2'?
   22 |                         pref[i][j]=(pref[i-1][j]+pref[i-1][j-1]*j*4+pref[i-1][j-2]*C2(j)+pref[i-2][j-1]*(i-1)*j)%MOD;
      |                                                                                    ^~
      |                                                                                    c2