【leetcode 刷题笔记1】hash table 哈希算法

哈希表

 

1、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, and you may not use the same element twice.

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

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

C++解法

class Solution {
public:
    vector twoSum(vector &numbers, int target)  //声明函数twoSum 为int类型的数组； 函数传入 int类型的数组 &numbers, int类型的 target
    {
        unordered_map m; //
        vector result;
        for(int i=0;i