一个数组nums，其中任意两个值等于给定值target…

2018-09-10 01:03:10来源：博客园阅读 ()

 1 package com.java.tencent;
 2 
 3 import java.lang.reflect.Array;
 4 import java.util.Arrays;
 5 import java.util.HashMap;
 6 import java.util.Map;
 7 
 8 public class T_1_twoSum {
 9 
10     /*初级解法*/
11     public int[] twoSum(int[] nums, int target) {
12         int[] result = new int[2];
13         for(int i=0;i<nums.length-1;i++){
14             for(int j=i+1;j<nums.length;j++){
15                 if(nums[i] + nums[j]==target){
16                     result[0] = i;
17                     result[1] = j;
18                     break;
19                 }
20             }
21         }
22         return result;
23     }
24     
25     /*中级解法*/
26     public int[] twoSum_yh(int[] nums, int target) {
27         Map<Integer,Integer> map = new HashMap<Integer,Integer>();
28         for(int i = 0; i < nums.length; i++){
29             map.put(nums[i], i);
30         }
31         for(int i = 0; i < nums.length; i++){
32             int complement = target - nums[i];
33             if(map.containsKey(complement) && map.get(complement) != i){
34                 return new int[]{ i, map.get(complement) };
35             }
36         }
37         throw new IllegalArgumentException("No two sum solution");
38     }
39     
40     /*高级解法*/
41     public int[] twoSum_yh_max(int[] nums, int target) {
42         Map<Integer,Integer> map = new HashMap<Integer,Integer>();
43         for(int i = 0; i < nums.length; i++){
44             int complement = target - nums[i];
45             if(map.containsKey(complement)){
46                 return new int[]{map.get(complement), i };
47             }
48             map.put(nums[i], i);
49         }
50         throw new IllegalArgumentException("No two sum solution");
51     }
52     
53     public static void main(String[] args) {
54         /*nums数组任意两个值等于target，返回数据在nums里的位置*/
55         int[] nums = {3,2,3};
56         int target = 6;
57         T_1_twoSum aa = new T_1_twoSum();
58         System.out.println(Arrays.toString(aa.twoSum(nums, target)));
59         
60         System.out.println(Arrays.toString(aa.twoSum_yh(nums, target)));
61         
62         System.out.println(Arrays.toString(aa.twoSum_yh_max(nums, target)));
63     }
64 
65 }