Sections and issues (DFS)

Partial and problem time limits:MS | Memory limit:65535 KB Difficulty:2

Describe

given an integer a1, A2 、....... an, determine whether a number can be selected from it, so that their and exactly k.

Input

First, N and K,n represent the number of numbers, and K represents the number of the numbers. Then the number of rows N. (1<=n<=20, guaranteed not to exceed int range)

Output

If and exactly can be K, output "yes", and in the order of input sequentially output is by which number and composition, otherwise "NO"

Sample input

4 131 2) 4 7

Sample output

YES2 4 7

Solution: This problem with dynamic planning should also be able to write, and time efficiency, with a backpack write down, decisive wrong, thinking has problems;

1#include <stdio.h>2#include <stack>3 using namespacestd;4 intm[ +],n,k;5stack<int>num;6 BOOLDfsintTempinti) {7     if(i==n)returntemp==K;8         if(Dfs (temp,i+1))return true;9         if(Dfs (temp+m[i],i+1)){Ten Num.push (M[i]); One             return true; A         } -     return false; - } the intMain () { -      while(~SCANF ("%d%d",&n,&k)) { -          for(intI=0; i<n;++i) scanf ("%d",&m[i]); -         if(Dfs (0,0)){ +printf"yes\n"); -              for(intI=0;! Num.empty (); i++){ +                 if(i) printf (" "); Aprintf"%d", Num.top ()); at Num.pop (); -             } -Puts""); -     } -     Elseprintf"no\n"); -     } in     return 0; -}

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Sections and issues (DFS)