Two Sum

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.

Example:

Given nums = [2, 7, 11, 15], target = 9,

Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1].

 UPDATE (2016/2/13):

The return format had been changed to zero-based indices. Please read the above updated description carefully.

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#include<iostream>
#include<map>
#include<vector>
using namespace std;
class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        vector<int> res;
        map<int,int> hashmap;
        int find_num;
        for(int i=0;i<nums.size();i++)
        {
            find_num=target-nums[i];
            map<int,int>::iterator it=hashmap.find(find_num);
            if(it!=hashmap.end())
            {
                res.push_back(i);
                res.push_back(it->second);
                return res;
            }
            hashmap[nums[i]]=i;
        }
    }
};