力扣-两数之和

题目描述：

class Solution {
    public int[] twoSum(int[] nums, int target) {
        int[] indexs = new int[2];
        //创建hashmap
        HashMap<Integer,Integer> hash = new HashMap<Integer,Integer>();
        for(int i = 0; i < nums.length; i++){
            if(hash.containsKey(nums[i])){
                indexs[0] = i;
                indexs[1] = hash.get(nums[i]);
                return indexs;
            }
            // 两数查存入 ，value为下标
            hash.put(target-nums[i],i);
        }
        return indexs;
    }
}