1. Two Sum Leetcode Python

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


The function twoSum shocould 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 wowould have exactly one solution.


Input: numbers = {2, 7, 11, 15}, target = 9

Output: index1 = 1, index2 = 2

This topic is from introduction to algorithm and describes the usage of brute force.

Here we use hashtable to set the value as the key value as the index and use target-num [index] As the search condition. Similar questions include 4 sum.

The Code is as follows:

class Solution:    # @return a tuple, (index1, index2)    def twoSum(self, num, target):        process={}        for index in range(len(num)):            if target-num[index] in process:                return [process[target-num[index]]+1,index+1]            process[num[index]]=index