nyoj 927 深搜

题目链接：http://acm.nyist.edu.cn/JudgeOnline/problem.php?pid=927

AC代码：

#include<cstdio>
#include<iostream>
#include<cstring>
using namespace std;
int visited[22],p[22],sum,N,K,flag;
void dfs(int n)
{
	if(flag==0)
	{
		if(sum==K)
		{
			flag=1;
			printf("Of course,I can!\n");
		}
		else
		{
			for(int i=n;i<N;i++)
			{
				if(visited[i]==0&&sum<K)
				{
					sum+=p[i];
					visited[i]=1;
					dfs(i+1);
					sum-=p[i];
					visited[i]=0;
				}
			}
		}
	}
}
int main()
{
	while(~scanf("%d",&N))
	{
		memset(visited,0,sizeof(visited));
		memset(p,0,sizeof(p));
		sum=0,flag=0;
		for(int i=0;i<N;i++)
		{
			scanf("%d",&p[i]);
		}
		scanf("%d",&K);
		dfs(0);
		if(flag==0)
		{
			printf("Sorry,I can't!\n");
		}
	}
	return 0;
}