04 2020 档案

leetcode 30 days challenge Check If a String Is a Valid Sequence from Root to Leaves Path in a Binary Tree
摘要：Check If a String Is a Valid Sequence from Root to Leaves Path in a Binary Tree Given a binary tree where each path going from the root to any leaf fo 阅读全文
posted @ 2020-04-30 20:09 qwfand 阅读(511) 评论(3) 推荐(0)
LeetCode First Unique Number
摘要：First Unique Number You have a queue of integers, you need to retrieve the first unique integer in the queue. Implement the FirstUnique class: FirstUn 阅读全文
posted @ 2020-04-28 21:37 qwfand 阅读(372) 评论(0) 推荐(0)
letcode1143 Longest Common Subsequence
摘要：letcode1143 Longest Common Subsequence Longest Common Subsequence Given two strings text1 and text2, return the length of their longest common subsequ 阅读全文
posted @ 2020-04-26 16:07 qwfand 阅读(144) 评论(0) 推荐(0)
Leetcode 560 Subarry Sum Equals K
摘要：Leetcode 560 Subarry Sum Equals K Given an array of integers and an integer k, you need to find the total number of continuous subarrays whose sum equ 阅读全文
posted @ 2020-04-22 18:43 qwfand 阅读(151) 评论(0) 推荐(0)
leetcode Leftmost Column with at Least a One
摘要：leetcode Leftmost Column with at Least a One (This problem is an interactive problem.) A binary matrix means that all elements are 0 or 1. For each in 阅读全文
posted @ 2020-04-21 17:15 qwfand 阅读(449) 评论(0) 推荐(0)
Leetcode 1254. Number of Closed Islands
摘要：Leetcode 1254. Number of Closed Islands Given a 2D grid consists of 0s (land) and 1s (water). An island is a maximal 4 directionally connected group o 阅读全文
posted @ 2020-04-17 21:28 qwfand 阅读(233) 评论(0) 推荐(0)
Leetcode 200. Number of Islands
摘要：Leetcode 200. Number of Islands 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 阅读全文
posted @ 2020-04-17 20:57 qwfand 阅读(142) 评论(0) 推荐(0)
LeetCode 455. Assign Cookies
摘要：LeetCode 455. Assign Cookies Assume you are an awesome parent and want to give your children some cookies. But, you should give each child at most one 阅读全文
posted @ 2020-04-15 15:32 qwfand 阅读(81) 评论(0) 推荐(0)
leetcode Perform String Shifts
摘要：Perform String Shifts You are given a string s containing lowercase English letters, and a matrix shift, where shift[i] = [direction, amount]: directi 阅读全文
posted @ 2020-04-14 16:00 qwfand 阅读(348) 评论(0) 推荐(0)
leetcode 494. Target Sum
摘要：leetcode 494. Target Sum You are given a list of non negative integers, a1, a2, ..., an, and a target, S. Now you have 2 symbols + and . For each inte 阅读全文
posted @ 2020-04-12 00:25 qwfand 阅读(125) 评论(0) 推荐(0)
leetcode 543. Diameter of Binary Tree
摘要：leetcode 543. Diameter of Binary Tree Given a binary tree, you need to compute the length of the diameter of the tree. The diameter of a binary tree i 阅读全文
posted @ 2020-04-11 18:48 qwfand 阅读(131) 评论(0) 推荐(0)
leetcode 746. Min Cost Climbing Stairs(easy understanding dp solution)
摘要：leetcode 746. Min Cost Climbing Stairs(easy understanding dp solution) On a staircase, the i th step has some non negative cost cost[i] assigned (0 in 阅读全文
posted @ 2020-04-10 13:53 qwfand 阅读(116) 评论(0) 推荐(0)
leetcode 213. House Robber II
摘要：leetcode 213. House Robber II You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed. A 阅读全文
posted @ 2020-04-10 09:50 qwfand 阅读(104) 评论(0) 推荐(0)
leetcode 198. House Robber
摘要：leetcode 198. House Robber You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the 阅读全文
posted @ 2020-04-10 08:51 qwfand 阅读(91) 评论(0) 推荐(0)
leetcode 120. Triangle
摘要：leetcode 120. 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. Fo 阅读全文
posted @ 2020-04-09 21:06 qwfand 阅读(132) 评论(0) 推荐(0)
leetcode 64. Minimum Path Sum
摘要：leetcode 64. Minimum Path Sum Given a m x n grid filled with non negative numbers, find a path from top left to bottom right which minimizes the sum o 阅读全文
posted @ 2020-04-09 18:52 qwfand 阅读(83) 评论(0) 推荐(0)
leetcode 63. Unique Paths II
摘要：leetcode 63. Unique Paths II A robot is located at the top left corner of a m x n grid (marked 'Start' in the diagram below). The robot can only move 阅读全文
posted @ 2020-04-09 18:12 qwfand 阅读(108) 评论(0) 推荐(0)
leetcode 62. Unique Paths
摘要：leetcode 62. Unique Paths A robot is located at the top left corner of a m x n grid (marked 'Start' in the diagram below). The robot can only move eit 阅读全文
posted @ 2020-04-09 17:54 qwfand 阅读(136) 评论(0) 推荐(0)
leetcode 30 day challenge Counting Elements
摘要：Counting Elements Given an integer array arr, count element x such that x + 1 is also in arr. If there're duplicates in arr, count them seperately. Ex 阅读全文
posted @ 2020-04-07 23:30 qwfand 阅读(164) 评论(0) 推荐(0)
leetcode 49. Group Anagrams
摘要：leetcode 49. Group Anagrams Given an array of strings, group anagrams together. Example: Input: ["eat", "tea", "tan", "ate", "nat", "bat"], Output: [ 阅读全文
posted @ 2020-04-06 16:51 qwfand 阅读(118) 评论(0) 推荐(0)
leetcode 122. Best Time to Buy and Sell Stock II
摘要：leetcode 122. Best Time to Buy and Sell Stock II 相关链接 "leetcode" 描述 Say you have an array for which the ith element is the price of a given stock on d 阅读全文
posted @ 2020-04-06 00:14 qwfand 阅读(201) 评论(0) 推荐(0)
leetcode 121. Best Time to Buy and Sell Stock
摘要：leetcode 121. Best Time to Buy and Sell Stock 相关链接 "leetcode" 描述 Say you have an array for which the ith element is the price of a given stock on day 阅读全文
posted @ 2020-04-05 23:30 qwfand 阅读(133) 评论(0) 推荐(0)
python 集合（set）和字典（dictionary）的用法解析
摘要：Table of Contents generated with "DocToc" "ditctaionary and set" "hash 介绍" "集合 set" "创建" "操作和访问集合的元素" "子集、超集、相对判断" "字典 dictionary （map）" "创建字典" "字典的基本 阅读全文
posted @ 2020-04-03 16:47 qwfand 阅读(2856) 评论(0) 推荐(0)
leetcode 53. Maximum Subarray
摘要：leetcode 53. Maximum Subarray 链接 "leetcode" 描述 Given an integer array nums, find the contiguous subarray (containing at least one number) which has th 阅读全文
posted @ 2020-04-03 16:17 qwfand 阅读(90) 评论(0) 推荐(0)
leetcode 202. Happy Number
摘要：leetcode 202. Happy Number 相关链接 "LeetCode" 描述 Write an algorithm to determine if a number is "happy". A happy number is a number defined by the follow 阅读全文
posted @ 2020-04-03 15:15 qwfand 阅读(105) 评论(0) 推荐(0)
leetcode 136.Single Number
摘要：136.Single Number 相关链接 "leetcode" 背景知识 Concept原理 If we take XOR of zero and some bit, it will return that bit a⊕0=a（0异或任何数得任何数） If we take XOR of two 阅读全文
posted @ 2020-04-01 19:46 qwfand 阅读(128) 评论(0) 推荐(0)
leetcode 703. Kth Largest Element in a Stream & c++ priority_queue & minHeap/maxHeap
摘要：703. Kth Largest Element in a Stream & c++ priority_queue & minHeap/maxHeap 相关链接 "leetcode" "c++ priority_queue cplusplus" "c++ priority_queue cnblog" 阅读全文
posted @ 2020-04-01 09:48 qwfand 阅读(134) 评论(0) 推荐(0)