#include<stdio.h>
#define MAXSIZE 50
#define MAXS 25
int w[MAXSIZE];
knapsack(int s,int m)
{
    typedef struct{
        int s;
        int m;
    }stackelem;
    stackelem stack[MAXS];
    int i,t,top,nofail;
    t=0;
    top=0;
    nofail=1;
    while((s!=t)  &&  nofail)
    {
        if((s>=t+w[1]) && (m>0))
        {
            stack[top].s=w[m];
            stack[top].m=m;
            top++;
            t=t+w[m];
            m--;
        }
        else
        {
            if(m==0)
            {
                top--;
                t=t-stack[top].s;
            }
            if(top<1)  nofail=0;
            else
            {
                top--;
                m=stack[top].m-1;
                t=t-stack[top].s;
            }
        }
    }
    if(s==t)
       for(i=0;i<top;i++)
           printf("\n%d\n",stack[i].s);
    else printf("three is no any selection!");
}
int main()
{
    int s,m,i;
    int w[MAXSIZE];
    printf("Please input an array w:\n");
    scanf("%d",w);
    printf("Please input a data s:\n");
    scanf("%d",&s);
    i=knapsack(s,m);
    return i;
}