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2 votes
2 answers
598 views

Find max in-order difference in array

Given an array A of integers, find the maximum of j - i subjected to the constraint of ...
3 votes
1 answer
176 views

Find minimal modulo-sum of pairs from two lists

Recently I appeared for an job challenge organised on HackerEarth. Question: There are two teams T1 and T2. Power of each player is represented in array. The rules of game are as follow. There are ...
2 votes
1 answer
2k views

Rotate matrix 90 degrees

I recently did problem 1.7 Rotate Matrix in Cracking the Coding Interview. I realized my code is very different than what is in the book and also from what I'm finding online (I'm having trouble ...
2 votes
2 answers
891 views

Convert integer to English words

I was recently asked an interview question with regards to algorithm design. The challenge is as follows: Given a 6 or less digits positive integer (0 - 999999 inclusive), write a function ...
5 votes
2 answers
113 views

Find minimal number of days to meet all your friends

I was asked this in an interview yesterday: You get an array of segments (segment contains 2 numbers, representing days count (say in a month, but could be in a year, etc.): start, end). You need to ...
5 votes
1 answer
115 views

An alternative algorithm for sorting a stack using only one additional stack

From "Cracking the Coding Interview": Write a program to sort a stack in ascending order (with biggest items on top). You may use at most one additional stack to hold items, but you may not copy the ...
4 votes
2 answers
511 views

Longest Palindromic Substring better approach

I have encountered to this question and applied a brute force algorithm off top of my head and couldn't find a better optimized solution. I was hoping I could get some insight to implement a better ...
7 votes
6 answers
2k views

Find max number you can create from an array of numbers

Was asked this in an interview yesterday: You are given an array of numbers (not digits, but numbers: e.g. 9, 23, 184, 102, etc.) - you need to construct the largest number from it. For example: you ...
4 votes
2 answers
908 views

Find the in-order successor of a given node in a binary search tree

I have an implementation of an algorithm to return the in-order successor of a given node in a binary search tree. We are allowed to assume that each node in the BST has a reference to its parent node....
3 votes
1 answer
210 views

Find contiguous integers with a given sum

Introduction This question was asked in a technical interview, I am looking for some feedback on my solution. Given a list of integers and a number K, return which contiguous elements of the list ...
12 votes
3 answers
8k views

Vertically print a list of strings to STDOUT into 3 columns with column lengths as balanced as possible

This was a interview question I struggled with, I am posting my solution hoping to look for more elegant/efficient solutions. Problem: Given a list of strings, print its element out to STDOUT one by ...
2 votes
1 answer
1k views

Longest Valid Parentheses

This is the "Longest Valid Parentheses" problem from leetcode.com: Given a string containing just the characters "(" and ")", ...
1 vote
1 answer
920 views

Solving "Quadruple sum" problem using dynamic programming

I am trying to learn dynamic programming using hash table. I was given this the "Quadruple sum" problem from firecode.io as a challenge: Given a sorted array of integers and an integer target, find ...
5 votes
1 answer
2k views

Ukkonen's algorithm for longest common substring search

I am working on a programming interview practice question in Python 3 (on codefights.com). The challenge is to return the length of the longest substring that appears in both of two input strings. The ...
10 votes
2 answers
287 views

Python implementation of find_all_indexes

I got asked this question before in an interview. For example, find_all_indexes('ababc', 'abc') returns 2. This Python function ...

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