leetcode第1题two sum

下面是Java的代码：

class Solution {
    public int[] twoSum(int[] nums,int target){
        int[] result = new int[2];
        for (int i = 0; i < nums.length; i++){
            for (int j = i + 1;j < nums.length; j++){
                if(nums[i] + nums[j] == target){
                    result[0] = i;
                    result[1] = j;
                }
            }
        }
        return result;
    }
}

class Solution {
    public int[] twoSum(int[] nums,int target){
        int[] result = new int[2];
        Map<Integer,Integer> mp = new HashMap<Integer, Integer>();
        for (int i  = 0; i < nums.length; i++){
            if(mp.containsKey(target - nums[i])){
                result[0] = mp.get(target - nums[i]);
                result[1] = i;
                return  result;
            }
            mp.put(nums[i],i);
        }
        return result;
    }
}

下面是Python的代码：

class Solution:
    def twoSum(self, nums, target: int):
        mp = {}
        for i, x in enumerate(nums):
            if x in mp:
                return mp[x], i
            else:
                mp[target - x] = i
        return -1

第1题是简单题，迈出了第一步，以后也不要停下噢！