👨‍🏫 力扣 两数之和

在一个数组中如何快速找到某一个数的互补数：哈希表 O(1)实现

⭐ AC code

class Solution {public int[] twoSum(int[] nums, int target){HashMap<Integer, Integer> map = new HashMap<>();for (int i = 0; i < nums.length; i++){if (map.containsKey(target - nums[i]))return new int[] { map.get(target - nums[i]), i };map.put(nums[i], i);}return new int[0];}
}