原创 leetcode 228:Summary Ranges

leetcode 228:Summary Ranges 題目： Given a sorted integer array without duplicates, return th

2020-02-21 12:03:48

原创 leetcode 202:Happy number

題目： Write an algorithm to determine if a number is “happy”. A happy number is a number defined by the following proces

2018-09-03 21:46:11

原创 leetcode 203:Remove Linked List Elements

題目： Remove all elements from a linked list of integers that have value val. Example Given: 1 –> 2 –> 6 –> 3 –> 4 –> 5

2018-09-03 21:46:10

原创 leetcode 58:Length of Last Word

題目： Given a string s consists of upper/lower-case alphabets and empty space characters ’ ‘, return the length of last

2018-09-03 21:46:10

原创 leetcode 155:Min Stack

題目： Design a stack that supports push, pop, top, and retrieving the minimum element in constant time. push(x) -- Push

2018-09-03 21:46:09

原创 leetcode 198:House Robber

題目： You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stas

2018-09-03 21:46:09

原创 機器學習入門-各種名稱

        要開始下面的學習，首先必須瞭解機器學習的分類，根據不同的分類標準，我們會有不同的分類結果，這些名稱在以後的機器學習中我們總會遇到，不同類型的問題我們會有不同的解決辦法。        一、根據輸出空間劃分：        

2018-09-03 21:46:09 1

原创 快速排序

今天學習了快速排序算法，實現了基本快速排序和三向切分快速排序，其中三向切分對於有大量重複數據的情況有很好的作用。 package Code; import java.util.Random; public class QuickSor

2018-09-03 21:46:09

原创 leetcode 225:Implement Stack using Queues

題目： Implement the following operations of a stack using queues. push(x) -- Push element x onto stack. pop() -- Remove

2018-09-03 21:46:09

原创 leetcode 70:Climbing Stairs

題目： 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.

2018-09-03 21:46:09

原创 leetcode 190:Reverse Bits

題目： Reverse bits of a given 32 bits unsigned integer. For example, given input 43261596 (represented in binary as 0000

2018-09-03 21:46:09

原创 leetcode 205:Isomorphic Strings

題目： Given two strings s and t, determine if they are isomorphic. Two strings are isomorphic if the characters in s can

2018-09-03 21:46:09

原创 leetcode 191:Number of 1 Bits

題目： Write a function that takes an unsigned integer and returns the number of ’1’ bits it has (also known as the Hammi

2018-09-03 21:45:52 2

原创 leetcode 204:Count Primes

題目： Description: Count the number of prime numbers less than a non-negative number, n. 分析： 本題是要統計0~n的素數個數，這個要根據hint中

2018-09-03 21:45:52

原创 leetcode 66:plus one

題目： Given a non-negative number represented as an array of digits, plus one to the number. The digits are stored such

2018-09-03 21:45:52