#哈希表 #两数之和

two-sum.cpp

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