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Leetcode 213: House Robber II

Posted on June 28, 2018

Question You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed. All houses at this place are arranged in a circle. That means the first house is the neighbor of the last one. Meanwhile, adjacent houses have security system... [Read More]

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Leetcode 198: House Robber

Posted on June 28, 2018

Question You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopping you from robbing each of them is that adjacent houses have security system connected and it will automatically contact the police if two adjacent... [Read More]

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Leetcode 200: Number of Islands

Posted on June 28, 2018

Question Given a 2d grid map of ‘1’s (land) and ‘0’s (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of the grid are all surrounded by water. [Read More]

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Disjoint Set Union

Posted on June 28, 2018

A Disjoint Set Union (DSU) data structure can be used to maintain knowledge of the connected components of a graph, and query for them quickly. In particular, we would like to support two operations: [Read More]

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Leetcode 179: Largest Number

Posted on June 28, 2018

Question Given a list of non negative integers, arrange them such that they form the largest number. [Read More]

Leetcode 173: Binary Search Tree Iterator

Posted on June 27, 2018

Question Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST. [Read More]

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Leetcode 172: Factorial Trailing Zeroes

Posted on June 27, 2018

Question Given an integer n, return the number of trailing zeroes in n!. [Read More]

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Leetcode 168: Excel Sheet Column Title

Posted on June 27, 2018

Question Given a positive integer, return its corresponding column title as appear in an Excel sheet. [Read More]

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Leetcode 162: Find Peak Element

Posted on June 27, 2018

Question A peak element is an element that is greater than its neighbors. [Read More]

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Leetcode 161: One Edit Distance

Posted on June 27, 2018

Question Given two strings s and t, determine if they are both one edit distance apart. [Read More]

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Leetcode 160: Intersection of Two Linked Lists

Posted on June 24, 2018

Question Write a program to find the node at which the intersection of two singly linked lists begins. [Read More]

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Leetcode 156: Binary Tree Upside Down

Posted on June 24, 2018

Question Given a binary tree where all the right nodes are either leaf nodes with a sibling (a left node that shares the same parent node) or empty, flip it upside down and turn it into a tree where the original right nodes turned into left leaf nodes. Return the... [Read More]

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