HDU 2519.新生晚会

题目:http://acm.hdu.edu.cn/showproblem.php?pid=2519

AC代码(C++):

#include <iostream>#include <algorithm>#include <stdio.h>#include <vector>#include <queue>#include <math.h>#include <string>#include <string.h>#include <bitset>#define INF 0x3f3f3f3f#define LFINF 1e10#define eps 1e-7#define MAXN 100105#define PI 3.14159265358979323846using namespace std;int n,m;int C[40][40];void table(){    C[0][0] = 1;    for(int i=1;i<=35;i++)    {        C[i][0] = 1;        for(int j=1;j<=i;j++)            C[i][j] = C[i-1][j]+C[i-1][j-1];    }}int main(){    table();    int t;    cin>>t;    while(t--){        cin>>n>>m;        if(n<m)cout<<0<<endl;        else cout<<C[n][m]<<endl;    }}

总结: 组合数打表.