You are given a perfect binary tree where all leaves are on the same level, and every parent has two children. The binary tree has the following definition: 1 2 3 4 5 6 struct Node { int val; Node *left; Node *right; Node *next; } Populate each next pointer to point to its next right node. If there is no next right node, the next pointer should be set to NULL. ...
Given a matrix of M x N elements (M rows, N columns), return all elements of the matrix in diagonal order as shown in the below image. Example: Input: [ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ] ] Output: [1,2,4,7,5,3,6,8,9] Explanation: Note: The total number of elements of the given matrix will not exceed 10,000. Solution: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 class Solution { public int[] findDiagonalOrder(int[][] A) { if (A == null || A.length == 0) { return new int[]{}; } int rows = A.length; int cols = A[0].length; int[] list = new int[rows * cols]; int row = 0; int col = 0; int direction = 1; for (int i = 0; i < list.length; i++) { list[i] = A[row][col]; if (direction == 1) { if (col == cols - 1) { direction = -1; row++; } else if (row == 0) { col++; direction = -1; } else { row--; col++; } } else { if (row == rows - 1) { col++; direction = 1; } else if (col == 0) { row++; direction = 1; } else { row++; col--; } } } return list; } }
A message containing letters from A-Z is being encoded to numbers using the following mapping: 1 2 3 4 'A' -> 1 'B' -> 2 ... 'Z' -> 26 Given a non-empty string containing only digits, determine the total number of ways to decode it. 1 2 3 4 5 Example 1: Input: "12" Output: 2 Explanation: It could be decoded as "AB" (1 2) or "L" (12). 1 2 3 4 5 Example 2: Input: "226" Output: 3 Explanation: It could be decoded as "BZ" (2 26), "VF" (22 6), or "BBF" (2 2 6). Solution: ...
Given a linked list, return the node where the cycle begins. If there is no cycle, return null. To represent a cycle in the given linked list, we use an integer pos which represents the position (0-indexed) in the linked list where tail connects to. If pos is -1, then there is no cycle in the linked list. Note: Do not modify the linked list. Example 1: Input: head = [3,2,0,-4], pos = 1 Output: tail connects to node index 1 Explanation: There is a cycle in the linked list, where tail connects to the second node. ...
Given a binary string s and an integer k. Return True if every binary code of length k is a substring of s. Otherwise, return False. Example 1: 1 2 3 Input: s = "00110110", k = 2 Output: true Explanation: The binary codes of length 2 are "00", "01", "10" and "11". They can be all found as substrings at indicies 0, 1, 3 and 2 respectively. Example 2: ...
Given a list of daily temperatures T, return a list such that, for each day in the input, tells you how many days you would have to wait until a warmer temperature. If there is no future day for which this is possible, put 0 instead. For example, given the list of temperatures T = [73, 74, 75, 71, 69, 72, 76, 73], your output should be [1, 1, 4, 2, 1, 1, 0, 0]. ...
Given a binary tree, write a function to get the maximum width of the given tree. The maximum width of a tree is the maximum width among all levels. The width of one level is defined as the length between the end-nodes (the leftmost and right most non-null nodes in the level, where the null nodes between the end-nodes are also counted into the length calculation. It is guaranteed that the answer will in the range of 32-bit signed integer. ...
Given an array nums of n integers, are there elements a, b, c in nums such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero. Note: The solution set must not contain duplicate triplets. 1 2 3 4 5 6 7 8 9 Example: Given array nums = [-1, 0, 1, 2, -1, -4], A solution set is: [ [-1, 0, 1], [-1, -1, 2] ] Solution: ...
Given a list of lists of integers, nums, return all elements of nums in diagonal order as shown in the below images. Example 1: 1 2 Input: nums = [[1,2,3],[4,5,6],[7,8,9]] Output: [1,4,2,7,5,3,8,6,9] Example 2: 1 2 Input: nums = [[1,2,3,4,5],[6,7],[8],[9,10,11],[12,13,14,15,16]] Output: [1,6,2,8,7,3,9,4,12,10,5,13,11,14,15,16] Example 3: 1 2 Input: nums = [[1,2,3],[4],[5,6,7],[8],[9,10,11]] Output: [1,4,2,5,3,8,6,9,7,10,11] Example 4: ...
There are 8 prison cells in a row, and each cell is either occupied or vacant. Each day, whether the cell is occupied or vacant changes according to the following rules: If a cell has two adjacent neighbors that are both occupied or both vacant, then the cell becomes occupied. Otherwise, it becomes vacant. (Note that because the prison is a row, the first and the last cells in the row can’t have two adjacent neighbors.) ...