//2018.11.22_10.39
class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        unordered_map<int,int> hashmap;
        vector<int> vt;
        for(int i=0;i<nums.size();i++){
            hashmap[nums[i]]=i;
        }
        for(int i=0;i<
 
nums.size();i++){
            if(hashmap[target-nums[i]]!=hashmap.end()&&hashmap[target-nums[i]]!=i]){
                vt.push_back(i);
                vt.push_back(hashmap[target-nums[i]]);
                return vt;
            }            
        }
    }
};

2018.11.22_11.01
class Solution {
 

public:
    vector<int> twoSum(vector<int>& nums, int target) {
        unordered_map<int,int> hashmap;
        vector<int> vt;
        for(int i=0;i<nums.size();i++){
            hashmap.insert(pair<int,int>(nums[i],i));
        }
        for(int i=0;i<nums.size
 
();i++){
            if(hashmap.find(target-nums[i])!=hashmap.end()&&hashmap[target-nums[i]]!=i){
                vt.push_back(i);
                vt.push_back(hashmap[target-nums[i]]);
                return vt;
            }            
        }
    }
};