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Algorithms

LeetCode#34: Find First and Last Position of Element in Sorted Array

This LeetCode problem is a great practice problem to implement a binary search for a value in a sorted array with duplicate values. It asks to find the indices of the first and start the occurrence of a value in the sorted array with possibly duplicate values. It can be solved in a naive manner […]

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Algorithms

LeetCode#75: Sort Color using Three-way Partitioning

The Sort Color problem expects to sort the array with values {0, 1, 2}. This can be done in a typical sorting algorithm in O(nlogn) time. A better approach is to use three-way partitioning of the array. Generic three-way partitioning Below the threeWayPartitionSort() method splits the given an array, [3,2,0,2,1,1,0,-1], into three parts, where values […]

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Algorithms Data Science

Stock Prediction Using Deep Learning

Recently have been looking into some stock market prediction libraries and repositories for our group project for CS7643 Deep Learning at Georgia Tech. Previously I worked on traditional Machine Learning algorithms and Q-Learning algorithm from Reinforcement Learning for CS7646: Machine Learning for Trading commonly known as the “ML4T course”. My codes for ML4T is locked […]

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Algorithms

LeetCode: Find Peak Element Solution

The Find Peak Element problem can be solved using a linear search in O(n) time and O(1) space. but it can be even better to solve it by binary search in O(log n) time complexity. But there can be two cases for binary search solution, the recursive solution creates stacks for each call and thus […]

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Algorithms

LeetCode: Kth Largest Element in an Array using QuickSelect with Hoare Partition

Find Kth Largest Element in an Array is a problem which can be solved using e.g. QuickSort in O(nlogn) time and then pick the k-th element in the sorted array. Another way is to sort it using QuickSelect in O(n) times. The solution below beats 100% Java submissions on LeetCode for runtime. QuickSelect QuickSelect is […]

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Algorithms Data Science

Resources to Understand Transformer Architecture in NLP

Posting some great resources to understand the Transformer architecture for NLP presented in the paper “Attention is All You Need” (Vaswani et al. 2017). This website by J Al-Ammar is excellent The next best resource is this annotated implementation of Transformer in PyTorch from Harvard University Second, read this article called “Attention! Attention!” by Lilian […]