UVa 11806 - Cheerleaders (组合计数+容斥原理)

《训练指南》p.108

#include <cstdio>
#include <cstring>
#include <cstdlib>

using namespace std;

const int MOD = ;

const int MAXN = ;

int C[MAXN][MAXN];

void init()
{
    memset( C, , sizeof(C) );
    C[][] = ;
    for ( int i = ; i < MAXN; ++i )
    {
        C[i][] = C[i][i] = ;
        for ( int j = ; j < i; ++j )
        C[i][j] = ( C[i-][j] + C[i-][j-] ) % MOD;
    }
    return;
}

int main()
{
    init();
    int T, cas = ;
    scanf( "%d", &T );
    while ( T-- )
    {
        int M, N, K;
        int ans = ;
        scanf( "%d%d%d", &M, &N, &K );
        for ( int S = ; S < (  <<  ); ++S )
        {
            int cnt = ;
            int r = M, c = N;
            if ( S &  ) --r, ++cnt;
            if ( S &  ) --r, ++cnt;
            if ( S &  ) --c, ++cnt;
            if ( S &  ) --c, ++cnt;
            if ( cnt &  ) ans = ( ans + MOD - C[r*c][K] )%MOD;
            else ans = ( ans + C[r*c][K] )%MOD;
        }
        printf( "Case %d: %d\n", ++cas, ans );
    }
    return ;
}