LeetCode:Tow Sum程序以及分析

URL:https://leetcode.com/problems/two-sum/description/
Given an array of integers, return indices of the two numbers such that they add up to a specific target.

You may assume that each input would have exactly one solution, and you may not use the same element twice.

Example:

Given nums = [2, 7, 11, 15], target = 9,Because nums[0] + nums[1] = 2 + 7 = 9,return [0, 1].

Code:

class Solution {public:    vector<int> twoSum(vector<int>& nums, int target) {        map<int,int> array;        vector<int> result;        for(int i = 0;i < nums.size(); i ++)        {            array[nums[i]] = i;        }        for(int i = 0;i < nums.size(); i ++)        {            result.push_back(i);            int dif = target - nums[i];            if(array.find(dif) != array.end() && i != array[dif])            {                result.push_back(array[dif]);                return result;            }               else                result.pop_back();        }    }};