POJ1306(组合数公式)

题意：求Cnm

分析：组合数公式。C(n,m)=C(n-1,m-1)+C(n-1,m)

代码：

#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
const int maxn = 110;
double c[maxn][maxn];
int main()
{
     int n, m;
    while(scanf("%d%d", &n, &m) != EOF&&(m||n))
    {
        for(int i = 0; i < 101; i++)
        {
         c[i][0] = 1;
         c[i][i] = 1;
        }
        for(int i = 2; i < 101; i++)
            for(int j = 1; j < i; j++)
            c[i][j] = c[i-1][j] + c[i-1][j-1];
            printf("%d things taken %d at a time is %.0f exactly.
", n, m, c[n][m]);
    }
    return 0;
}