UVa 11806 - Cheerleaders

http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&category=226&problem=2906&mosmsg=Submission+received+with+ID+11832924

容斥原理  第二题  水！

代码：

#include<iostream>
#include<cstring>
#include<cstdio>
#include<string>
#include<set>
#include<map>
#include<cmath>
#include<algorithm>
#include<vector>
#include<cmath>
#include<queue>
#include<stack>

//#define ull unsigned long long
#define ll long long

using namespace std;

const int INF=0x3f3f3f3f;
const int MOD=1000007;

const double eps=1e-6;
const int N=500;
int c[N][N];
int F(int x)
{
    if(x>=MOD)
    {
        x=x%MOD;
        return x;
    }
    while(x<0)
    {
        x+=MOD;
    }
    return x;
}
int main()
{
    //freopen("data.in","r",stdin);
    memset(c,0,sizeof(c));
    for(int i=0;i<N;++i)
    for(int j=0;j<=i;++j)
    if(i==j||j==0)
    c[i][j]=1;
    else
    c[i][j]=(c[i-1][j]+c[i-1][j-1])%MOD;

    int T;
    cin>>T;
    for(int w=1;w<=T;++w)
    {
        printf("Case %d: ",w);
        int n,m,k;
        cin>>n>>m>>k;
        if(k>n*m||k<2)
        cout<<"0"<<endl;
        else
        {
            int sum=0;
            sum+=(2*c[n*m-n][k]+2*c[n*m-m][k]);//cout<<sum<<endl;
            sum-=(c[n*m-n-n][k]+c[n*m-m-m][k]+4*c[n*m-m-n+1][k]);
            sum+=(2*c[n*m-m-m-n+2][k]+2*c[n*m-m-n-n+2][k]);
            sum-=(c[n*m-n-n-m-m+4][k]);
            cout<<F(c[n*m][k]-sum)<<endl;
        }

    }
    return 0;
}