CODEWITHSUNDEEP
pythonpython-3.x
Wizard
Wizard

Reputation: 22043

Problem in Linear search to solve a twoSum problem

I tried the easiest problem in Leecodes to solve a twoSum,

The problems:

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.

My Conceptual Plan: Fix the first number and find (target - first)
Used: an O(n) iteration * O(n) linear search 

from typing import List 
class Solution:
    def twoSum(self, nums: List[int], target: int) -> List[int]:
        for i in range(len(nums)):  #loop 
            find = target - nums[i]
            print(i, find)
            for j in range(i, len(nums)):#linear search 
                if find == nums[j]:
                    print(j)
                    return [i, j]
        return None

When tried to check it

In [51]: Solution().twoSum(nums, target)                                                                                      
0 3
0
Out[51]: [0, 0]

Failed to find the problems and depressed to be stuck with the easiest problem in leecode.

Upvotes: 1

Views: 48

Answers (1)

Nick Nikolov
Nick Nikolov

Reputation: 261

Try looping from i + 1 to len(nums) in the second loop as you cannot use the same element twice. Other than that it looks correct.

Upvotes: 2

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