SWUST OJ(963)

小偷的背包

 #include<stdio.h>
 #include<stdlib.h>

 int s, flag, n, *a; //主函数之外定义的变量为全局变量

 void dfs(int index, int count, int * a)
 {
     if(count == s)
     {
         flag = ;
         return;
     }

     if (index > n)
     {
         return;
     }

     dfs(index + , count + a[index], a);
     dfs(index + , count, a);
 }

 int main(int argc, char const *argv[])
 {
     scanf("%d",&s);
     scanf("%d",&n);

     a = (int*)malloc(n*sizeof(int));

     for (int i = ; i < n; ++i)
     {
         scanf("%d",&a[i]);
     }

     dfs(, , a);

     if (flag)
     {
         printf("yes!");
     }
     else
     {
         printf("no!");
     }
     return ;
 }