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) return null; // 用来存放之前扫描过的元素,key-存储的值,value-存储的索引 Map<Integer, Integer> map = new HashMap<>(); for (int i = 0; i < numbers.length; i++) { Integer idx = map.get(target - numbers[i]); if (idx != null) return new int[] {idx+1, i+1}; map.put(numbers[i], i); } return null; } }
解题思想:哈希存值+结果值判断