@rkenmi - Search Results

Stack Memory vs. Heap Memory

... = faster lookup Can result in the dreaded stack overflow Heap Memory The heap memory is used within the context of an application, which may use one or more threads.

May 28, 2019

... keep track of the smallest values. Since there are \(k\) linked lists, we can use a binary heap to keep track of \(k\) nodes, since we only need to keep track of at most \(k\) nodes with distinct indices.

February 9, 2019

Algorithm Handbook

... find min/max k problems by recording the row and column of the 2D matrix value as an entry in the heap, allowing you to effectively find sorted values in less than \(O(n^2)\) time. For rotating a 2d array, there is a 2-step program Transpose the matrix (Turn Columns to Rows): [[1, 2],[3, 4]] => [[1, 3],[2, 4]] Invert the rows (mirror): [1, 2, 3] => [3, 2, 1] # Transpose a 2d matrix for j in range(0, n): for i in range(j, n): matrix[i][j], matrix[j][i] = matrix[j][i], matrix[i][j] Linked Lists Use a slow and a fast pointer for linked list nodes To get to the half-way point of a linked list efficiently, simply increment the fast pointer by 2 and the slow pointer by 1.

June 18, 2017

Java Essentials

... will excel for cross-platform support due to the JVM. Heap vs. Stack The heap is a part of memory that is reserved for allocation of reference types (i.e. Objects).

March 29, 2019

Javascript Essentials

... Empty set let s = new Set(); Set with values let s = new Set([1, 2, 3]); Min heap goog.require('goog.structs.Heap'); let h = new goog.structs.

November 12, 2017

Python Essentials

... = {'a': 'b'} Empty set s = set() Set with values s = set([1, 2, 3]) Min heap import heapq q = [] heapq.heappush(q, 1) heapq.

April 3, 2019

Algorithm Interview Problems

Welcome This page contains solutions to common interview problems that may be encountered. Arrays Longest Substring Without Repeating Characters Rotate a 2D Matrix Buy/Sell Two Stocks Merge Intervals Next Permutation Random Permutation Replace all occurrences of a space with a string Linked Lists Reversing sublists of singly linked lists Cycles in singly linked lists Overlapping singly linked lists Merging two sorted singly linked lists Merge k sorted lists Recursion Counting the path of sums Money Denominations Phone Number Mnemonics Unique Permutation Dynamic Programming Perfect Squares Find the Maximum Min Path Binary Trees Tree Symmetry Iterative In-Order Traversal of a Binary Tree Construct a Binary Tree from Pre-Order Traversal and In-Order Traversal BST Validate a BST Binary Heaps Merge k sorted lists Graphs Find a path in a maze from start to finish Flip colors in a matrix Search Search in a rotated sorted array Find the Duplicate Number Greedy Algorithms Queue Reconstruction By Height Trie Build a Trie in Python Invariant Compute the max.