Author Archives: Arden

The title says it all, this is a pretty standard interview question. Generate all permutations of a given string.

Given an array of integers find the kth element in the sorted order (not the kth distinct element). So, if the array is [3, 1, 2, 1, 4] and k is 3 then the result is 2, because it’s the … Continue reading →

Given an array: convert it to: in-place using constant extra space.

Given a source word, target word and an English dictionary, transform the source word to target by changing/adding/removing 1 character at a time, while all intermediate words being valid English words. Return the transformation chain which has the smallest number … Continue reading →

This is a very common interview question. Given a binary tree, check whether it’s a binary search tree or not. Simple as that..

We are given 3 strings: str1, str2, and str3. Str3 is said to be a shuffle of str1 and str2 if it can be formed by interleaving the characters of str1 and str2 in a way that maintains the left … Continue reading →

This is a very fundamental question and it’s tricky to implement without any bugs. Given a linkedlist of integers and an integer value, delete every node of the linkedlist containing that value.

This question can be solved efficiently with a very clever trick. There is an array of non-negative integers. A second array is formed by shuffling the elements of the first array and deleting a random element. Given these two arrays, … Continue reading →

This is one of the most common interview practice questions. Given an array of integers (positive and negative) find the largest continuous sum.

This is a very elegant question which seems easy at first but requires some hard thinking to solve it efficiently: Given a matrix of integers and coordinates of a rectangular region within the matrix, find the sum of numbers falling … Continue reading →