leetcode [Two Sum]

public class Solution {//Java O（N^2）    public int[] twoSum(int[] nums, int target) {        int[] res = 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){                    res[0] = i;                    res[1] = j;                    return res;                }            }        }        return res;    }}

class Solution {//C++ 用到了map，能快一些，容器的好处public:    vector<int> twoSum(vector<int>& nums, int target) {        map<int, int> map_temp;        vector<int> res;        for(int i = 0; i < nums.size(); i++){            map_temp[nums[i]] = i;        }        for(int i = 0; i < nums.size(); i++){            int t = target - nums[i];            if(map_temp[t] && (map_temp[t] != i)){                res.push_back(i);                res.push_back(map_temp[t]);                return res;            }        }        return res;    }};