LeetCode算法题--刷题第一天

Given an array of integers, return indices of the two numbers such that they add up to a specific target.

You may assume that each input would have exactly one solution, and you may not use the same element twice.

（译：给定一个整数数组，返回两个数字的索引，使它们相加得到一个特定目标值。您可以假设每个输入都只有一个解决方案，而您可能不会使用相同的元素两次。）

Example:

Given nums = [2, 7, 11, 15], target = 9,
Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1]

 

 代码实现：（参考）

    import java.util.HashMap;  
    import java.util.Map;  
      
    public class Solution {  
        public static int[] twoSum(int[] nums, int target) {  
            int[] result = new int[2];  
            Map<Integer,Integer> map = new HashMap();  
            for(int i=0; i<nums.length; i++){  
                if(map.containsKey(target - nums[i])){  
                    if(map.get(target - nums[i]) > i){  
                        result[0] = i;  
                        result[1] = map.get(target - nums[i]);  
                    }else{  
                        result[1] = i;  
                        result[0] = map.get(target - nums[i]);  
                    }  
                    return result;  
                }  
                map.put(nums[i], i);  
            }  
            return result;  
        }  
          
        public static void main(String[] args) {  
            int[] nums = {3,2,4};  
            int target = 6;  
            int[] result = new int[2];  
            result = twoSum(nums,target);  
            System.out.println(result[0] + " " + result[1]);  
        }  
    }