POJ1664 DFS做法

题目地址：http://poj.org/problem?id=1664

#include<cstdio>int k,n;long r;void backtrack(long dep,long prev,long n){long m;if(dep==k&&n>=prev){r++;return;}for(m=prev;m<=n/2;m++)backtrack(dep+1,m,n-m);}int main(){int t;scanf("%d",&t);while(t--){scanf("%d%d",&n,&k);r=0;backtrack(1,0,n);   //0代表允许为空。如果不为空此行为 backtrack(1,1,n);printf("%d\n",r);}}