Submission #1692478

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Source Code Expand

#include <bits/stdc++.h>
#define pb push_back
#define Y second
#define X first
#define dbg(x) if(1)cerr<< #x << " = "<<x<<endl;
#define _ <<", "<<
#define fr(a,b,c) for(int a=b,__=c;a<__;a++)
using namespace std;
typedef long long ll;
const int mod=1e9+7;
int mdp[2001][2001];
ll dp[2001][2001][3];
ll go(int A,int B,int x){
	if(x==2)return 1;
	if(~dp[A][B][x])return dp[A][B][x];
	if(A){
		dp[A][B][x]=go(A-1,B,x);
	}
	else dp[A][B][x]=0;
	fr(i,0,min(A+1,B)){
		dp[A][B][x]+=go(A-i,i,x+1)*mdp[i][B-1];
		dp[A][B][x]%=mod;
	}
	return dp[A][B][x];
}
int main(){
	int a,b;
	scanf("%d%d",&a,&b);
	memset(dp,-1,sizeof dp);
	fr(j,0,b)fr(i,0,j+1){
		if(i==j)mdp[i][j]=1;
		else if(j==0&&i!=0)mdp[i][j]=0;
		else if(i)mdp[i][j]=mdp[i-1][j-1]+mdp[i][j-1];
		else mdp[i][j]=mdp[i][j-1];
		if(mdp[i][j]>=mod)mdp[i][j]-=mod;
	}
	fr(i,0,a+1)fr(x,0,2)dp[i][0][x]=1;
	fr(i,0,b+1)fr(x,0,2)dp[0][i][x]=1;
	fr(i,0,a+1)fr(j,0,b+1)dp[i][j][2]=1;
	printf("%lld\n",go(a,b,0));
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:28:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&a,&b);
                     ^

Judge Result