hdu 1258_Sum It Up hdu

深搜

#include<cstdio>#include<cstring>#include<iostream>#include<algorithm>using namespace std;int t,n,num[105];int ans[105],flag;void dfs(int x,int k,int sum){int i,j;int last=-1;if(sum>t)return ;if(sum==t){flag=1;cout<<ans[1];for(j=2;j<k;j++){printf("+%d",ans[j]);}cout<<endl;}for(i=x;i<=n;i++){if(sum+num[i]<=t&&last!=num[i]){ans[k]=num[i];last=num[i];dfs(i+1,k+1,sum+num[i]);}}}int main(){int i;while(cin>>t>>n&&t+n){for(i=1;i<=n;i++)cin>>num[i];flag=0;printf("Sums of %d:\n",t);if(num[n]>t){cout<<"NONE"<<endl;continue;}  else{dfs(1,1,0);if(!flag)cout<<"NONE"<<endl;}}return 0;}