Submission #883857

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Source Code Expand

#include<stdio.h>
long long Mod = 1000000007, Inv[4010000], F[4010000], InvF[4010000], D[2010][2010];
long long Comb(int a, int b){
    return F[a]*InvF[b]%Mod*InvF[a-b]%Mod;
}
int n, K;
int main(){
    int i, j;
    scanf("%d%d",&n,&K);
    if(K==1){
        printf("1\n");
        return 0;
    }
    Inv[1]=F[0]=InvF[0]=1;
    for(i=2;i<=n*K;i++){
        Inv[i] = Inv[Mod%i] * (Mod-Mod/i)%Mod;
    }
    for(i=1;i<=n*K;i++){
        F[i]=F[i-1]*i%Mod;
        InvF[i]=InvF[i-1]*Inv[i]%Mod;
    }
    for(i=0;i<=n;i++){
        for(j=i;j<=n;j++){
            if(i==0&&j==0)D[i][j]=1;
            if(i) D[i][j] = D[i-1][j];
            if(j>i) D[i][j] = (D[i][j] + D[i][j-1]* Comb(n*K - (n-i) - (n-j)*(K-1) - 1, K-2))%Mod;
        }
    }
    printf("%lld\n",D[n][n]*F[n]%Mod);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:9:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&K);
                        ^

Judge Result