随笔分类 - Leetcode
摘要：Given a non-empty string containing an out-of-order English representation of digits 0-9, output the digits in ascending order. Note: Example 1: Input
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摘要：Find the nth digit of the infinite integer sequence 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, ... Note:n is positive and will fit within the range of a 32-bi
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摘要：Given a positive integer n and you can do operations as follow: What is the minimum number of replacements needed for n to become 1? Example 1: Exampl
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摘要：Given an array of integers A and let n to be its length. Assume Bk to be an array obtained by rotating the array A k positions clock-wise, we define a
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摘要：You are given two jugs with capacities x and y litres. There is an infinite amount of water supply available. You need to determine whether it is poss
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摘要：You are given an array x of n positive numbers. You start at point (0,0) and moves x[0] metres to the north, then x[1] metres to the west, x[2] metres
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摘要：There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle every
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摘要：Given an integer n, count the total number of digit 1 appearing in all non-negative integers less than or equal to n. Example: Approach #1: Math. [Jav
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摘要：Implement a basic calculator to evaluate a simple expression string. The expression string may contain open ( and closing parentheses ), the plus + or
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摘要：We are given that the string "abc" is valid. From any valid string V, we may split V into two pieces X and Y such that X + Y (X concatenated with Y) i
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摘要：You have an array of logs. Each log is a space delimited string of words. For each log, the first word in each log is an alphanumeric identifier. Then
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摘要：We are given two arrays A and B of words. Each word is a string of lowercase letters. Now, say that word b is a subset of word a if every letter in b
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摘要：A string S of lowercase letters is given. Then, we may make any number of moves. In each move, we choose one of the first K letters (starting from the
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摘要：Given 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 a
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摘要：To some string S, we will perform some replacement operations that replace groups of letters with new ones (not necessarily the same size). Each repla
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摘要：We had some 2-dimensional coordinates, like "(1, 3)" or "(2, 0.5)". Then, we removed all commas, decimal points, and spaces, and ended up with the str
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摘要：Given an expression such as expression = "e + 8 - a + 5" and an evaluation map such as {"e": 1} (given in terms of evalvars = ["e"] and evalints = [1]
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摘要：X is a good number if after rotating each digit individually by 180 degrees, we get a valid number that is different from X. Each digit must be rotate
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摘要：Special binary strings are binary strings with the following two properties: The number of 0's is equal to the number of 1's. Every prefix of the bina
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摘要：You are given a string expression representing a Lisp-like expression to return the integer value of. The syntax for these expressions is given as fol
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