leetcode

Given an array of unique integers salary where salary[i] is the salary of the employee i. Return the average salary of employees excluding …

There is a robot starting at position (0, 0), the origin, on a 2D plane. Given a sequence of its moves, judge if this robot ends up at (0, …

Given an integer n, return a string with n characters such that each character in such string occurs an odd number of times. The returned s…

Balanced strings are those who have equal quantity of 'L' and 'R' characters. Given a balanced string s split it in the maximum amount of b…

Given a string s formed by digits ('0' - '9') and '#' . We want to map s to English lowercase characters as follows: Characters ('a' to 'i'…

International Morse Code defines a standard encoding where each letter is mapped to a series of dots and dashes, as follows: "a" maps to ".…

Implement function ToLowerCase() that has a string parameter str, and returns the same string in lowercase. 根据题意，遍历每个字符，如果 ascii 大于等于 65 小于…

It can be written as (A), where A is a VPS. depth(C) = 0, where C is a string with a single character not equal to "(" or ")". depth(A + B)…

Given two string arrays word1 and word2, return true if the two arrays represent the same string, and false otherwise. A string is represen…

You own a Goal Parser that can interpret a string command. The command consists of an alphabet of "G", "()" and/or "(al)" in some order. Th…

You are given an array of distinct integers arr and an array of integer arrays pieces, where the integers in pieces are distinct. Your goal…

Given a string s and an integer array indices of the same length. The string s will be shuffled such that the character at the ith position…

Given two strings s and t, your goal is to convert s into t in k moves or less. Choose any index j (1-indexed) from s, such that 1 <= …

Given a string containing only three types of characters: '(', ')' and '*', write a function to check whether this string is valid. We defi…

Given an array of integers nums, you start with an initial positive value startValue. In each iteration, you calculate the step by step sum…

Given two equal-size strings s and t. In one step you can choose any character of t and replace it with another character. Return the minim…

Balanced strings are those who have equal quantity of 'L' and 'R' characters. Given a balanced string s split it in the maximum amount of b…

Given 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 incr…

Given a column title as appear in an Excel sheet, return its corresponding column number. 根据题意，在将字母的二十六进制，转换为十进制，比较简单，时间复杂度为 O(N)，空间复杂度为 O(…

Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. For example, two is written as II in Roman numeral, just…