题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1799
2 1 3 2 3
3 3
PS:
组合求和:C(n, m) = C(n-1, m)+C(n-1, m-1);
代码如下:
#include <cstdio>
#include <cstring>
int dp[2017][2017];
void OP()
{
for(int i = 1; i <= 2000; i++)
{
dp[i][0] = 1;
dp[i][1] = i%1007;
}
for(int i = 2; i <= 2000; i++)
{
for(int j = 1; j <= 2000; j++)
{
dp[i][j] = (dp[i-1][j]+dp[i-1][j-1])%1007;
}
}
}
int main()
{
int t;
int n, m;
OP();
scanf("%d",&t);
while(t--)
{
scanf("%d%d",&m,&n);
printf("%d\n",dp[n][m]);
}
return 0;
}
原文地址:http://blog.csdn.net/u012860063/article/details/39321015