蓝桥杯练习题 和为T（DFS）

 1 import java.util.Scanner;
 2 
 3 public class Main {
 4     
 5     static int n,count,T;
 6     static int[] a = new int[22];
 7     static int[] b = new int[22];
 8     public static void main(String[] args) {
 9         // TODO Auto-generated method stub
10         
11     Scanner sc = new Scanner(System.in);
12     n =sc.nextInt();
13     
14     for(int i =0;i<n;i++)
15     {
16         a[i]=sc.nextInt();
17     }
18     T=sc.nextInt();
19     
20     count = 0;
21     findAns(n-1,0,0);
22     System.out.println(count);
23     
24 
25     }
26     
27     static void findAns(int aIndex, int bIndex, int sum)
28     {
29         if(aIndex < 0){
30             return;
31         }
32 
33 
34         findAns(aIndex-1, bIndex, sum);
35         b[bIndex] = a[aIndex];
36         sum += a[aIndex];
37         if(sum == T){
38             count ++;
39             print(bIndex);
40         }
41         findAns(aIndex-1, bIndex+1, sum);
42     }
43     
44     static  void print(int bIndex)
45     {
46         int i;
47 
48         for(i=bIndex; i>=0; i--){
49             System.out.print(b[i]+" ");
50         }   
51         System.out.println();
52 
53     }
54     
55 }