题解 | #两数之和#TOP50

思路:
1.两数之和，hashmap存取，看代码

import java.util.*;


public class Solution {
    /**
     * 
     * @param numbers int整型一维数组 
     * @param target int整型 
     * @return int整型一维数组
     */
    public int[] twoSum (int[] numbers, int target) {
        // write code here
          if(numbers == null || numbers.length < 2){
              return new int[]{-1,-1};
          }
        //数组值 数组下标
        HashMap<Integer,Integer> map = new HashMap<>();
        for(int i = 0; i< numbers.length; i++){
            if(map.containsKey(target - numbers[i])){
                return new int[]{map.get(target- numbers[i]) + 1, i + 1};
            }
            map.put(numbers[i], i);
        }
        return new int[]{-1,-1};
    }
}