Portfolio

Check Out Some of My Works.

From web development to game design, my portfolio showcases a diverse range of projects that reflect my passion, skills, and dedication to creating impactful digital experiences. Each project is a testament to my commitment to quality, innovation, and user-centric design. Dive in to explore my creations and get a glimpse of my journey in the world of technology.

Portfolio

Coding Challenges

Welcome to the Coding Challenges section, where I showcase my problem-solving skills through various coding exercises. These challenges range from fundamental algorithms to complex data structures, all solved using different programming paradigms. Each challenge includes a link to the source code on GitHub and the original problem statement on LeetCode. Dive in to explore my coding journey!

Longest Substring Without Repeating Characters

Python

Solved using the sliding window technique to maintain a set of unique characters within the current window.

View Code on GitHub View Problem on LeetCode

Search in Rotated Sorted Array

Python

Solved using a modified binary search algorithm to find the target element in a rotated sorted array. Achieves O(log n) runtime complexity.

View Code on GitHub View Problem on LeetCode

Pow(x, n)

Python

Solved using the Exponentiation by Squaring technique to optimize the calculation to O(log n) time complexity.

View Code on GitHub View Problem on LeetCode

Search a 2D Matrix

Python

Solved using binary search to find the target element in a 2D matrix with O(log(m\n)) time complexity.

View Code on GitHub View Problem on LeetCode

Majority Element II

Python

Solved using a hash table to find all elements that appear more than ⌊ n/3 ⌋ times in an integer array of size n. The time complexity is O(n) and the space complexity is O(n).

View Code on GitHub View Problem on LeetCode

Delete Node in a Linked List

Python

Solved by modifying the given node in-place. The value of the given node is replaced with the value of the next node, and the next node is then skipped, effectively deleting the node. The time complexity is O(1) and the space complexity is O(1).

View Code on GitHub View Problem on LeetCode

Product of Array Except Self

Python

Solved by using two passes through the array. The first pass calculates the product of all elements to the left of each element, and the second pass calculates the product of all elements to the right. These products are then multiplied to get the final result for each index. The algorithm runs in O(n) time and O(1) extra space complexity (excluding the output array).

View Code on GitHub View Problem on LeetCode

Prison Cells After N Days

Python

Solved by using a dictionary to keep track of previously seen states of the prison cells. This allows us to detect cycles and optimize the simulation. The algorithm runs in O(1) time for each day, with a maximum of 2^6 unique states, making the overall time complexity O(2^6) or O(1) for practical purposes. The space complexity is also O(2^6) or O(1).

View Code on GitHub View Problem on LeetCode

Longest Palindromic Substring

Python

Solved by using a two-pointer approach that expands around the center of the palindrome. The algorithm checks for palindromes of both odd and even lengths. The time complexity is O(n^2) as we iterate through each character in the string and expand around it, and the space complexity is O(1).

View Code on GitHub View Problem on LeetCode

K Closest Points to Origin

Python

Solved by calculating the Euclidean distance for each point to the origin and then sorting these distances. The k closest points are then returned. The time complexity is O(n log n) due to sorting, and the space complexity is O(n) for storing the distances.

View Code on GitHub View Problem on LeetCode

Number of Dice Rolls With Target Sum

Python

Solved using dynamic programming to count the number of ways to achieve each possible sum with the given number of dice and faces. The time complexity is O(n * k * target) and the space complexity is O(n * target). The answer is returned modulo 10^9 + 7.

View Code on GitHub View Problem on LeetCode

Portfolio

pictCTF Challenges

In this section, you'll find a curated list of challenges I've tackled in picCTF, a Capture The Flag competition that tests various cybersecurity skills. Each challenge listing includes the category of the challenge, a brief description, and a link to my solution on GitHub. These challenges have helped me hone my skills in areas such as web exploitation, cryptography, and more

"hideme" Challenge

forensics

Solved by employing digital forensics and steganography techniques to uncover a hidden flag within an image file. Utilized tools like `strings` and `binwalk` for analysis and extraction.

The flag: picoCTF{Hiddinng_An_imag3_within_@n_ima9e_96539bea}
View writeup on GitHub View Challenge on picoCTF

"basic-mod2" Challenge

cryptography

Solved using modular arithmetic and modular inverse to decrypt a given message.

The flag: picoCTF{1nv3r53ly_h4rd_8a05d939}
View writeup on GitHub View Challenge on picoCTF

"dont-use-client-side" Challenge

web-exploitation

Solved by exploiting the client-side JavaScript function that verifies the password. Demonstrates the dangers of client-side password verification.

The flag: picoCTF{no_clients_plz_7723ce}
View writeup on GitHub View Challenge on picoCTF

Hello, World.

I'm Avigail Hagay.

About

Let me introduce myself.

Skills

Resume

More of my credentials.

Education

Bachelor Degree

Hadassah Academic College

Portfolio

Check Out Some of My Works.

TMDB Movie Shop

Cookery-Club

Proxy-like URL Resource Downloader

Nasa Social Site

Bulls & Cows

Secure Product System

AI-Crafted Citizen Manager

Memory Matching Game

Circle The Cat

TMDB Movie Shop

Cookery Club - Recipes Application

Circle the Cat

NASA Social Site

Memory Matching Game

Proxy-like URL Resource Downloader

Bulls & Cows

Secure Product System

AI-Crafted Citizen Manager

Portfolio

Coding Challenges

Longest Substring Without Repeating Characters

Search in Rotated Sorted Array

Pow(x, n)

Search a 2D Matrix

Majority Element II

Delete Node in a Linked List

Product of Array Except Self

Prison Cells After N Days

Longest Palindromic Substring

K Closest Points to Origin

Number of Dice Rolls With Target Sum

Portfolio

pictCTF Challenges

"hideme" Challenge

"basic-mod2" Challenge

"dont-use-client-side" Challenge

Contact

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