leetCode Two Sum

寻找数组中和为目标数的两个数

最新推荐文章于 2024-03-02 21:28:00 发布

原创最新推荐文章于 2024-03-02 21:28:00 发布 · 356 阅读

0 ·

CC 4.0 BY-SA版权

leetCode 专栏收录该内容

39 篇文章

订阅专栏

本文介绍了一个算法，用于在给定数组中找到两个数，它们相加等于特定的目标数。通过使用哈希表，该算法可以在一次遍历数组后找到答案。

Given an array of integers, find two numbers such that they add up to a specific target number.

The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than index2. Please note that your returned answers (both index1 and index2) are not zero-based.

You may assume that each input would have exactly one solution.

Input: numbers={2, 7, 11, 15}, target=9
Output: index1=1, index2=2

class Solution {
public:
    vector<int> twoSum(vector<int> &numbers, int target) {
        map<int, int> m;
        vector<int> rst;


        for(int i = 0; i < numbers.size(); i++)
        {
            map<int, int>::iterator it = m.find(target - numbers[i]);
            if(it == m.end())
            {
                m[numbers[i]] = i + 1;
                continue;
            }


                rst.push_back(it->second);
                rst.push_back(i + 1);
                return rst;
            }


    }
};