kelly_fumiao的博客

412—Fizz BuzzWrite a program that outputs the string representation of numbers from 1 to n.But for multiples of three it should output “Fizz” instead of the number and for the multiples of five outp...

621— Task SchedulerGiven a char array representing tasks CPU need to do. It contains capital letters A to Z where different letters represent different tasks. Tasks could be done without original ord...

697—Degree of an ArrayGiven a non-empty array of non-negative integers nums, the degree of this array is defined as the maximum frequency of any one of its elements.Your task is to find the smallest...

592—Fraction Addition and SubtractionGiven a string representing an expression of fraction addition and subtraction, you need to return the calculation result in string format. The final result shoul...

395—Longest Substring with At Least K Repeating CharactersFind the length of the longest substring T of a given string (consists of lowercase letters only) such that every character in T appears no l...

2— Add Two NumbersYou are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two n...

70— Climbing StairsYou 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?Note: Given n ...

121— Best Time to Buy and Sell StockSay you have an array for which the ith element is the price of a given stock on day i.If you were only permitted to complete at most one transaction (i.e., buy ...

198— House RobberYou 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 ...

53— Maximum SubarrayGiven an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum.Example1:Input: [-2,1,-3,4,-1,2,1,-5,4]...

6 — ZigZag Conversion1. 题目描述2. 思路分析题目:遍历字符串， 确定有几行， 确定每个字符在第几行。 两个转折点：在第0行和第numRows-1行处，要改变方向，也就是curRow变量加一还是减一。3. Python代码:def convert(s: str, numRows: int): rowLength = min(len(s), num...

155— Min StackDesign a stack that supports push, pop, top, and retrieving the minimum element in constant time.push(x) – Push element x onto stack.pop() – Removes the element on top of the stack....

20— Valid ParenthesesGiven a string containing just the characters ‘(’, ‘)’, ‘{’, ‘}’, ‘[’ and ‘]’, determine if the input string is valid.An input string is valid if:Open brackets must be closed ...

398—Random Pick IndexGiven an array of integers with possible duplicates, randomly output the index of a given target number. You can assume that the given target number must exist in the array.Note...

856— Score of ParenthesesGiven a balanced parentheses string S, compute the score of the string based on the following rule:“()” has score 1“AB” has score A + B, where A and B are balanced parenth...

784— Letter Case PermutationGiven a string S, we can transform every letter individually to be lowercase or uppercase to create another string. Return a list of all possible strings we could create....

46— PermutationsGiven a collection of distinct integers, return all possible permutations.Example 1:Input: [1,2,3]Output:[[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]C++代码:class So...

Rotate StringWe are given two strings, A and B.A shift on A consists of taking string A and moving the leftmost character to the rightmost position. For example, if A = ‘abcde’, then it will be ‘bcd...

Palindrome NumberDetermine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward.Example 1:Input: 121Output: trueExample 2:Input: -121Outp...

Reverse IntegerGiven a 32-bit signed integer, reverse digits of an integer.Example 1:Input: 123Output: 321Example 2:Input: -123Output: -321Example 3:Input: 120Output: 21Note:Assume w...

Two SumGiven an array of integers, return indices of the two numbers such that they add up to a specific target.You may assume that each input would have exactly one solution, and you may not use ...

511—Valid Triangle NumberGiven an array consists of non-negative integers, your task is to count the number of triplets chosen from the array that can make triangles if we take them as side lengths o...

394— Decode StringGiven an encoded string, return it’s decoded string.The encoding rule is: k[encoded_string], where the encoded_string inside the square brackets is being repeated exactly k times. ...

3 — Longest Substring Without Repeating Characters1. 题目描述2. 思路分析题目:方法一：暴力枚举法（这种方法提交会超时Time Limit Exceeded）列举出所有的子序列，判断每一个子序列是否重复， 记录最大子序列。方法二：滑动窗口遍历字符串， 如果重复了，则左边的窗口往右滑动一个位置， 继续判断， 如果没...