C++ :

#include<iostream>  
#include<cstdio>  
using namespace std;  
  
#define  M 100  
class SumOfSub  
{  
    friend  void sumofsub();  
    private:  
      void Backtrack(int t);  
      int count;  
      int n;  
      int c;  
      int cw;  
      int x[M];  
      int bestx[M];  
      int num[M];  
};  
  
  
void SumOfSub::Backtrack(int t)  
{//搜索t第层  
    int i,j;  
    if(t>n)//到达叶子节点  
    {  
        if(cw == c && count ==0)  
        {  
            count++;  
            for(i=1;i<=n;i++)  
            {  
                if(x[i]==1)  
                {  
                    printf("%d ",num[i]);  
                }  
            }  
            printf("\n");  
        }  
        return;  
    }  
    else  
    {  
        if(cw+num[t]<= c)  
        {  
            cw+=num[t];  
            x[t]=1;  
            Backtrack(t+1);  
            cw-=num[t];  
        }  
        x[t]=0;  
        Backtrack(t+1);  
    }  
}  
  
void sumofsub()  
{  
    int i,j;  
    SumOfSub s;  
    s.cw = 0;  
    s.count =0;  
    scanf("%d %d",&s.n,&s.c);  
    for(j=1;j<=s.n;j++)  
    {  
        scanf("%d",&s.num[j]);  
    }  
    for(j=1;j<=s.n;j++)  
    {  
        s.x[j]=0;  
    }  
    s.Backtrack(1);  
     if(s.count == 0)  
     {  
         printf("No Solution!");  
     }  
}  
  
int main()  
{  
    sumofsub();  
    return 0;  
}