section and Problem algorithm code (C)

Title: Given integer a1, A2, ..., an, to determine whether a number can be selected from it, so that their and exactly k.

There are many solutions, the simplest solution is to use depth first search, time complexity O (2^n), not the optimal solution.

Code:

* * * * * main.cpp * * *  Created on:2014.7.13 * 
 This column more wonderful content: http://www.bianceng.cnhttp:// www.bianceng.cn/Programming/sjjg/
 *      author:spike 
 /
      
/*eclipse CDT, gcc 4.8.1*/
      
#include < stdio.h>  
      
bool Dfs (int i, int sum, int* A, int n, int k) {  
    if (i==n) return sum = k;  
    if (Dfs (i+1, Sum, A, n, K)) return true;  
    if (Dfs (i+1, Sum+a[i], A, n, K)) return true;  
    return false;  
}  
      
void Solve (int* A, int n, int k) {  
    if (Dfs (0,0,a,n,k)) printf ("yes\n");  
    else printf ("no\n");  
}  
      
      
int main (void)  
{  
    const int max_n =;  
    int A[max_n] = {1, 2, 4, 7};  
    int n = 4, k = 13; K-bit need to find the number  
      
    solve (A, n, k);  
      
    return 0;  
}

Output:

Yes

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