zoj 1711 Sum It Up //深搜

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居然没超时 ... ps:index 是关键字么 ...

#include<iostream>#include<stdio.h>#include<string.h>#include<stdlib.h>using namespace std;int t,n,flag,ll;int a[14],vis[14];char pr[1000][100];//int f[15]={1,2,4,8,16,32,64,128,256,512,1024,2048,4096};int cmp(const void *a,const void *b){return (*(int *)a)<(*(int *)b)? 1:-1;}void pri(){int kk=0;char st[100];for(int i=0;i<n;i++)if(vis[i]){int temp=a[i];while(temp!=0){st[kk++]=temp%10-'0';temp/=10;}}st[kk++]='\0';for(int i=0;i<ll;i++)if(strcmp(st,pr[i])==0) return ;strcpy(pr[ll++],st);kk=0;for(int i=0;i<n;i++)if(vis[i])  { if(!kk) printf("%d",a[i]),kk=1;else printf("+%d",a[i]); }printf("\n");}void dfs(int sum,int k){if(sum==t){ flag=1; pri(); return ;}if(sum>t) return ;for(int i=k;i<n;i++)if(!vis[i]){vis[i]=1;dfs(sum+a[i],i+1);vis[i]=0;}}int main(){while(scanf("%d %d",&t,&n)!=EOF&&n){for(int i=0;i<n;i++)scanf("%d",&a[i]);printf("Sums of %d:\n",t);memset(vis,0,sizeof(vis));qsort(a,n,sizeof(a[0]),cmp);ll =0;flag=0;dfs(0,0);if(!flag)printf("NONE\n");}return 0;}