Parts and problems (Nanyang oj1058) (DFS)

Partial and problem time limit: 1000 MS | memory limit: 65535 kb difficulty: 2

Description

Given integers A1, A2,... an, judge whether several numbers can be selected from them to make their sum exactly K.

Input

First, N and K, N represent the number of numbers, and K represent the sum of numbers.
Next, the number of N rows.
(1 <= n <= 20, which must not exceed the int range)

Output

If the sum can be K, "yes" is output, and the sum of which numbers is output in order of input. Otherwise, "no" is output"

Sample Input

4 131 2 4 7

Sample output

YES2 4 7

Simple Deep Search

#include<stdio.h>int n,k,a[30],visit[30],ans,ok;int dfs(int pos){if(ans>=k){if(ans==k){if(!ok){    ok=1;printf("YES\n");}for(int i=0;i<n;i++)    if(visit[i]) printf("%d ",a[i]);printf("\n");}return ok;}for(int i=pos;i<n;i++) {   ans+=a[i];   visit[i]=1;   dfs(i+1);   ans-=a[i];   visit[i]=0;}}int main(){while(scanf("%d %d",&n,&k)==2){for(int i=0;i<n;i++){scanf("%d",&a[i]);visit[i]=0;}ok=ans=0;dfs(0);if(!ok)printf("NO\n");}return 0;}

Parts and problems (Nanyang oj1058) (DFS)