10.N个整数中查找是否相加为K[深度搜索]

#include <iostream>
using namespace std;

int a[]={1,2,3,5};
int n=sizeof(a)/sizeof(int),k=12;

bool dfs(int i,int sum)
{
if(i==n)
return sum==k;
if(dfs(i+1,sum))
return true;
if(dfs(i+1,sum+a[i]))
return true;
return false;
}
int main()
{
if(dfs(0,0))
cout<<"yes";
else
cout<<"no";
return 0;
}