Michael - Michael's Blog (Page 3)

Find All Anagrams in a String

438. Find All Anagrams in a String [https://leetcode.com/problems/find-all-anagrams-in-a-string/] Given a string s and a non-empty string p, find all the start indices of p's anagrams in s. Strings consists of lowercase English letters only and the length of both strings s and p will not be

LeetCode

Binary Tree Level Order Traversal

102. Binary Tree Level Order Traversal [https://leetcode.com/problems/binary-tree-level-order-traversal/] LintCode-69.Binary Tree Level Order Traversal [http://www.lintcode.com/en/problem/binary-tree-level-order-traversal] Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example: Given binary tree

LeetCode

Word Break II

140. Word Break II [https://leetcode.com/problems/word-break-ii/] Given a non-empty string s and a dictionary wordDict containing a list of non-empty words, add spaces in s to construct a sentence where each word is a valid dictionary word. You may assume the dictionary does not contain duplicate words.

LeetCode

Permutations II

Permutations II [https://leetcode.com/problems/permutations-ii/] Given a collection of numbers that might contain duplicates, return all possible unique permutations. For example, [1,1,2] have the following unique permutations: [ [1,1,2], [1,2,1], [2,1,1] ] public class Solution { public List> permuteUnique(int[] nums)

LeetCode

Binary Tree Vertical Order Traversal

314. Binary Tree Vertical Order Traversal [https://leetcode.com/problems/binary-tree-vertical-order-traversal] Given a binary tree, return the vertical order traversal of its nodes' values. (ie, from top to bottom, column by column). If two nodes are in the same row and column, the order should be from left to right.

Array

Rotate Image

48. Rotate Image [https://leetcode.com/problems/rotate-image/] You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees (clockwise). Follow up: Could you do this in-place? public class Solution { public void rotate(int[][] matrix) { if (matrix == null) { return; } int n = matrix.length;

Hash Table

Valid Sudoku

36. Valid Sudoku [https://leetcode.com/problems/valid-sudoku/] Determine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules. The Sudoku board could be partially filled, where empty cells are filled with the character '.'. Note: A valid Sudoku board (partially filled) is not necessarily solvable. Only

Array

Search Insert Position

35. Search Insert Position [https://leetcode.com/problems/search-insert-position/] Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order. You may assume no duplicates in the array. Here are

LeetCode

Reverse Nodes in k-Group

25. Reverse Nodes in k-Group [https://leetcode.com/problems/reverse-nodes-in-k-group/] Given a linked list, reverse the nodes of a linked list k at a time and return its modified list. If the number of nodes is not a multiple of k then left-out nodes in the end should remain as

LeetCode

3Sum

15. 3Sum [https://leetcode.com/problems/3sum/] LintCode-57.3Sum [http://www.lintcode.com/en/problem/3sum] Given an array S of n integers, are there elements a, b, c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero.

Regular Expression Matching

10. Regular Expression Matching [https://leetcode.com/problems/regular-expression-matching/] Implement regular expression matching with support for '.' and '*'. '.' Matches any single character. '*' Matches zero or more of the preceding element. The matching should cover the entire input string (not partial). The function prototype

LeetCode

ZigZag Conversion

6. ZigZag Conversion [https://leetcode.com/problems/zigzag-conversion/] The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility) P A H N A P L S I I G

LeetCode

Longest Palindromic Substring

5. Longest Palindromic Substring [https://leetcode.com/problems/longest-palindromic-substring/] Given a string s, find the longest palindromic substring in s. You may assume that the maximum length of s is 1000. Example: Input: "babad" Output: "bab" Note: "aba" is also a valid answer. Example: Input: "cbbd" Output: "bb" public class

LeetCode

Median of Two Sorted Arrays

4. Median of Two Sorted Arrays [https://leetcode.com/problems/median-of-two-sorted-arrays/] There are two sorted arrays nums1 and nums2 of size m and n respectively. Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)). Example 1: nums1 = [1, 3] nums2

LeetCode

Number of Connected Components in an Undirected Graph

323. Number of Connected Components in an Undirected Graph [https://leetcode.com/problems/number-of-connected-components-in-an-undirected-graph/] Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to find the number of connected components in an undirected

LeetCode

Linked List Random Node

382. Linked List Random Node [https://leetcode.com/problems/linked-list-random-node/] Given a singly linked list, return a random node's value from the linked list. Each node must have the same probability of being chosen. Follow up: What if the linked list is extremely large and its length is unknown to

LintCode

First Position of Target

LintCode-14.First Position of Target > For a given sorted array (ascending order) and a target number, find the first index of this number in O(log n) time complexity. > If the target number does not exist in the array, return -1. > Example > If the array is [1, 2, 3, 3,

LintCode

Find Minimum in Rotated Sorted Array II

LintCode-160.Find Minimum in Rotated Sorted Array II [http://www.lintcode.com/en/problem/find-minimum-in-rotated-sorted-array-ii/] > Suppose a sorted array is rotated at some pivot unknown to you beforehand. > (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). > Find the minimum element.

iOS

Swift 3 Migration Issues

As you already know that Swift 3 is released [https://swift.org/blog/swift-3-0-released/], I guess you guys are busy migrating your project to Swift 3 now. So this post I just list some issues I came across during migrating to Swift 3. 1.Instance method 'application(:didFinishLaunchingWithOptions:)' nearly

LintCode

Remove Duplicates from Unsorted List

LintCode-217.Remove Duplicates from Unsorted List [http://www.lintcode.com/en/problem/remove-duplicates-from-unsorted-list/] > Write code to remove duplicates from an unsorted linked list. > Example > Given 1->3->2->1->4. > Return 1->3->2->4 > Challenge > (hard) How would you solve this problem if a temporary buffer is not allowed?

LintCode

Longest Words

LintCode-133.Longest Words [http://www.lintcode.com/en/problem/longest-words/] > Given a dictionary, find all of the longest words in the dictionary. > Example > Given { "dog", "google", "facebook", "internationalization", "blabla" } > the longest words are(is) ["internationalization"]. > Given { "like", "love", "hate", "yes" } > the longest words are ["like", "love", "hate"]. > Challenge > It's easy

LintCode

Rotate List

LintCode-170.Rotate List [http://www.lintcode.com/en/problem/rotate-list/] > Given a list, rotate the list to the right by k places, where k is non-negative. > Example > Given 1->2->3->4->5 and k = 2, return 4->5->1->2->3. /** * Definition for singly-linked list. * public class ListNode { * int

LintCode

Triangle

LintCode-109. Triangle [http://www.lintcode.com/en/problem/triangle/] > Given a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below. > Notice > Bonus point if you are able to do this using only O(n) extra space, where

LintCode

Climbing Stairs

LintCode-111.Climbing Stairs [http://www.lintcode.com/en/problem/climbing-stairs/] > You are climbing a stair case. It takes n steps to reach to the top. > Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top? > Example > Given an example

LintCode

House Robber

LintCode-392.House Robber [http://www.lintcode.com/en/problem/house-robber/] > 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