class Solution(object):
    def twoSum(self, nums, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: List[int]
        """
        hash_map = dict()
        for i, v in enumerate(nums):
            k = target - v
            if k in hash_map:
                return [hash_map[k], i]
            hash_map[v] = i

老师，有个疑问，以下得这个时间复杂度不也是n平方吗？放入map也有一层循环不是？
public int[] twoSum(int[] nums, int target) {
    Map<Integer, Integer> map = new HashMap<>();
    for (int i = 0; i < nums.length; i++) {
        map.put(nums[i], i);
    }
    for (int i = 0; i < nums.length; i++) {
        int complement = target - nums[i];
        if (map.containsKey(complement) && map.get(complement) != i) {
            return new int[] { i, map.get(complement) };
        }
    }
    throw new IllegalArgumentException("No two sum solution");
}

怎么看自己实现的算法排行
go实现


func twoSum(nums []int, target int) []int {
    var nums_flip map[int]int
    nums_flip = make(map[int]int)
    var r [] int
    for i, v := range nums {
        nums_flip[v] = i
    }
    for i, v := range nums {
        var tag2 = target - v
        if i2, ok := nums_flip[tag2]; ok {
            if i !=i2 {
                r = append(r, i)
                r = append(r, i2)
                return r
            }
        }
    }
    
    return r
   
}