Valerie的博客

拓扑序[Special judge]在图论中，拓扑序（Topological Sorting）是一个有向无环图（DAG, Directed Acyclic Graph）的所有顶点的线性序列.

Excel Sheet Column NumberGiven a column title as appear in an Excel sheet, return its corresponding column number.

Minimum Moves to Equal Array ElementsGiven a non-empty integer array of size n, find the minimum number of moves required to make all array elements equal, where a move is incrementing n - 1 elements by 1.

Best Time to Buy and Sell Stock IIDesign an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy one and sell one share of the stock multiple times).

Find Smallest Letter Greater Than TargetGiven a list of sorted characters letters and given a target letter target, find the smallest element in the list that is larger than the given target.

Course ScheduleThere are a total of n courses you have to take, labeled from 0 to n - 1.Given the total number of courses and a list of prerequisite pairs, is it possible for you to finish all courses?

Strings J representing the types of stones that are jewels, and S representing the stones you have. Each character in S is a type of stone you have. You want to know how many of the stones are also jewels.

Find Anagram MappingsGiven two lists A and B, and B is an anagram of A. We want We want to We want to find an index mapping P, from A to B. A mapping P[i] = j means the ith element in A appears in B at index j

A matrix is Toeplitz if every diagonal from top-left to bottom-right has the same element. Now given an M x N matrix, return True if and only if the matrix is Toeplitz.

804. Unique Morse Code Words804. Unique Morse Code Words题目解决题目Leetcode题目International Morse Code defines a standard encoding where each letter is mapped to a series of dots and das...

Range Addition IIGiven an m * n matrix M initialized with all 0's and several update operations. You need to count and return the number of maximum integers in the matrix after performing all the operations.

Construct the RectangleFor a web developer, it is very important to know how to design a web page's size. So, given a specific rectangular web page’s area, your job by now is to design a rectangular web page.

Convert BST to Greater TreeGiven a BST, convert it to a Greater Tree such that every key of the original BST is changed to the original key plus sum of all keys greater than the original key in BST.

最小和从数列A[0], A[1], A[2], ..., A[N-1]中选若干个数，要求对于每个i（0<=i<N-1），A[i]和A[i+1]至少选一个数，求能选出的最小和.

最长公共子串给定两个字符串x = x­1x­2…x­n和y = y­1y­2…ym, 请找出x和y的最长公共子串的长度，也就是求出一个最大的k，使得存在下标i和j有x­ix­i+1…x­i+k-1 = yjy­j+1…y­j+k-1.

Sum of Two IntegersCalculate the sum of two integers a and b, but you are not allowed to use the operator + and -.

Find the DifferenceGiven two strings s and t which consist of only lowercase letters.String t is generated by random shuffling string s and then add one more letter at a random position.

Move ZeroesGiven an array nums, write a function to move all 0's to the end of it while maintaining the relative order of the non-zero elements.

Two Sum IV - Input is a BSTGiven a Binary Search Tree and a target number, return true if there exist two elements in the BST such that their sum is equal to the given target.

Construct String from Binary TreeYou need to construct a string consists of parenthesis and integers from a binary tree with the preorder traversing way.

算法概论 8.3题目STINGY SAT is the following problem: given a set of clauses (each a disjunction of literals) and an integer k, find a satisfying assignment in which at most k variables are true, if

Flood FillAn image is represented by a 2-D array of integers.Given a coordinate (sr, sc) representing the starting pixel (row and column) of the flood fill, and a pixel value newColor, "flood fill" the image.

762. Prime Number of Set Bits in Binary Representation762. Prime Number of Set Bits in Binary Representation题目解决题目Leetcode题目Given two integers L and R, find the count of numbers in...

784. Letter Case Permutation784. Letter Case Permutation题目解决题目Leetcode题目Given a string S, we can transform every letter individually to be lowercase or uppercase to create another ...

You are given an array A of strings. Two strings S and T are special-equivalent if after any number of moves, S == T. A move consists of choosing two indices i and j with i % 2 == j % 2. Return the number of groups of special-equivalent strings.

On a N * N grid, we place some 1 * 1 * 1 cubes. Each value v = grid[i][j] represents a tower of v cubes placed on top of grid cell (i, j). Return the total surface area of the resulting shapes.

In a string S of lowercase letters, these letters form consecutive groups of the same character. Call a group large if it has 3 or more characters. We would like the starting and ending positions of every large group.

Given a Binary Search Tree (BST) with the root node root, return the minimum difference between the values of any two different nodes in the tree.

Given a paragraph and a list of banned words, return the most frequent word that is not in the list of banned words. It is guaranteed there is at least one word that isn't banned, and that the answer is unique.

Return an integer array ans where ans[0] is the size of the candy bar that Alice must exchange, and ans[1] is the size of the candy bar that Bob must exchange.

Given two strings S and T, return if they are equal when both are typed into empty text editors. # means a backspace character.

At a lemonade stand, each lemonade costs $5. Customers are standing in a queue to buy from you, and order one at a time (in the order specified by bills).Each customer will only buy one lemonade and pay with either a $5, $10, or $20 bill. You must pro

788. Rotated Digits788. Rotated Digits题目解决题目Leetcode题目X is a good number if after rotating each digit individually by 180 degrees, we get a valid number that is different from X....

An array is monotonic if it is either monotone increasing or monotone decreasing. Return true if and only if the given array A is monotonic.

Given an n-ary tree, return the postorder traversal of its nodes' values.

Given a n-ary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

806. Number of Lines To Write String806. Number of Lines To Write String题目解决题目Leetcode题目We are to write the letters of a given string S, from left to right into lines. Each line ha...

811. Subdomain Visit Count811. Subdomain Visit Count题目解决题目Leetcode题目A website domain like “discuss.leetcode.com” consists of various subdomains. At the top level, we have “com”, at...

812. Largest Triangle Area812. Largest Triangle Area题目解决题目Leetcode题目You have a list of points in the plane. Return the area of the largest triangle that can be formed by any 3 of...

Implement function ToLowerCase() that has a string parameter str, and returns the same string in lowercase.