Leetcode Solutions

• 

  [Solved] Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right, which minimizes the sum of all numbers along its path.

• 

  [Solved] You are given an m x n integer array grid. There is a robot initially located at the top-left corner (i.e., grid[0][0]). The robot tries to move to the bottom-right corner (i.e., grid[m-1][n-1]). The robot can only move either down or right at any point in time. An obstacle and space are marked as 1 or 0 respectively in grid. A path that the robot takes cannot include any square that is an obstacle.

• 

  [Solved] There is a robot on an m x n grid. The robot is initially located at the top-left corner (i.e., grid[0][0]). The robot tries to move to the bottom-right corner (i.e., grid[m – 1][n – 1]). The robot can only move either down or right at any point in time. Given the two integers m and n, return the number of possible unique paths that the robot can take to reach the bottom-right corner.

• 

  [Solved] Given the head of a linked list, rotate the list to the right by k places.

• 

  [Solved] Given a string s consisting of words and spaces, return the length of the last word in the string. A word is a maximal substring consisting of non-space characters only.

• 

  [Solved] You are given an integer array nums. You are initially positioned at the array’s first index, and each element in the array represents your maximum jump length at that position. Return true if you can reach the last index, or false otherwise.

• 

  [Solved] Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum.

• 

  [Solved] Implement pow(x, n), which calculates x raised to the power n (i.e., xn).

• 

  [Solved] Given an array of strings strs, group the anagrams together. You can return the answer in any order. An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.

• 

  [Solved] You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise). You have to rotate the image in-place, which means you have to modify the input 2D matrix directly. DO NOT allocate another 2D matrix and do the rotation.

• 

  [Solved] Given a collection of numbers, nums, that might contain duplicates, return all possible unique permutations in any order.

• 

  [Solved] Given an array nums of distinct integers, return all the possible permutations. You can return the answer in any order.

• 

  [Solved] Given an array of non-negative integers nums, you are initially positioned at the first index of the array. Each element in the array represents your maximum jump length at that position.

• 

  [Solved] Given two non-negative integers num1 and num2 represented as strings, return the product of num1 and num2, also represented as a string. Note: You must not use any built-in BigInteger library or convert the inputs to integer directly.

• 

  [Solved] Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it can trap after raining.

• 

  [Solved] Given an unsorted integer array nums, return the smallest missing positive integer. You must implement an algorithm that runs in O(n) time and uses constant extra space.

• 

  [Solved] Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sum to target. Each number in candidates may only be used once in the combination.

• 

  [Solved] Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. You may return the combinations in any order.

• 

  [Solved] The count-and-say sequence is a sequence of digit strings defined by the recursive formula: countAndSay(1) = “1”, countAndSay(n) is the way you would “say” the digit string from countAndSay(n-1), which is then converted into a different digit string.

• 

  [Solved] Write a program to solve a Sudoku puzzle by filling the empty cells. A sudoku solution must satisfy all of the following rules: Each of the digits 1-9 must occur exactly once in each row.