2SUM Code with Corgis

LeetCode with Corgis and Kittens — Solving the Two Sum Problem!!!

LeetCode with Corgis Comic GIF 🎁 Issue #1 — Two Sum

Hello 👋💻🌎 Tech World,

LeetCode with Corgis and Kittens Problem #1 — Two Sum

MAKING LEARNING HOW TO CODE

✧・ﾟ:* CUTE(◕‿◕✿) and INFORMATIVEᕙ(⇀‸↼‶)ᕗ!!!

See repo below this comic. Hope you enjoy it!

Problem Statement

Given an array of integers, return indices of the 2️⃣ 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 item twice.

Example:

Given nums = [2, 11, 7, 15], target🎯 = 9,

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

Two Sum Animation

Coding Corgi with LeetKitty 2Sum Problem Animation

Approach 1: Brute Force

Java☕

Java Brute Force Approach

JavaScript💛

Brute Force Approach JavaScript

Python 🐍

Brute Force Approach Python

Complexity Analysis — Brute Force Approach:

• Time complexity ⏰: O(n²). For each number🔢, we try to find its difference/complement by looping through the rest of the list of numbers🔢 which takes O(n) time. Therefore, the Time Complexity is O(n²).

• Space complexity🚀: O(1).

Approach 2: Two-pass [HashTable/Object/Dictionary]

Step 1. Create a Hash Map/Object/Dictionary

Step 1. Create a Hash map/object/dictionary

Step 2. Loop through and check if the target value — nums[index] is in the dictionary

Java☕

Two-Pass Hash Table Approach Java

JavaScript💛

Two-Pass Object JavaScript

Python 🐍

Two-Pass Dictionary Approach

Complexity Analysis — Two-Pass Approach:

• Time complexity ⏰: O(n) We go through the list of n numbers exactly twice. Using the [hash table☕/dictionary🐍/object💛] reduces the lookup time to O(1), the Time Complexity is O(n).

• Space complexity🚀: O(n). The extra space required depends on the number of items stored in the [hash table☕/dictionary🐍/object💛] which stores exactly n numbers.

Approach 3: One-pass [Hash Table/Object/Dictionary]

Java☕

One Pass Object Approach Java with Corgis

JavaScript💛

One Pass Object Approach JavaScript with Corgis

Python 🐍

One Pass Object Approach Python with Corgis

Complexity Analysis — One Pass Approach:

• Time complexity ⏰: O(n). We traverse the list containing n numbers🔢 only once. Each lookup in the table costs only O(1) time.

• Space complexity🚀: O(n). The extra space required depends on the number of items stored in the [hash table☕/dictionary🐍/object💛], which stores at most n numbers🔢.

Start the next Question Right Meow!!!!

Thank you for reading ❤,

Kodie The Coding Corgi & Bits The A.I.

codewithcorgis/LeetCode-With-Corgis

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