1. 两数之和 - 力扣（LeetCode）

class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        unordered_map<int,int> map1;
        for(int i=0;i<nums.size();++i) map1[nums[i]] = i;
        for(int i=0;i<nums.size();++i){
            if(map1.find(target-nums[i])!=map1.end() && i!=map1[target-nums[i]])
            {
                return {i, map1[target-nums[i]]};
            }
        }
        return {};
    }
};