随笔分类 - LeetCode
摘要：We are given non-negative integers nums[i] which are written on a chalkboard. Alice and Bob take turns erasing exactly one number from the chalkboard,
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摘要：Sometimes people repeat letters to represent extra feeling, such as "hello" -> "heeellooo", "hi" -> "hiiii". Here, we have groups, of adjacent letters
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摘要：There are two types of soup: type A and type B. Initially we have N ml of each type of soup. There are four kinds of operations: Serve 100 ml of soup
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摘要：In a 2 dimensional array grid, each value grid[i][j] represents the height of a building located there. We are allowed to increase the height of any n
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摘要：We have a grid of 1s and 0s; the 1s in a cell represent bricks. A brick will not drop if and only if it is directly connected to the top of the grid,
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摘要：We are to write the letters of a given string S, from left to right into lines. Each line has maximum width 100 units, and if writing a letter would c
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摘要：International Morse Code defines a standard encoding where each letter is mapped to a series of dots and dashes, as follows: "a" maps to ".-", "b" map
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摘要：We start at some node in a directed graph, and every turn, we walk along a directed edge of the graph. If we reach a terminal node (that is, it has no
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摘要：We have two integer sequences A and B of the same non-zero length. We are allowed to swap elements A[i] and B[i]. Note that both elements are in the s
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摘要：In the following, every capital letter represents some hexadecimal digit from 0 to f. The red-green-blue color "#AABBCC" can be written as "#ABC" in s
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摘要：We stack glasses in a pyramid, where the first row has 1 glass, the second row has 2 glasses, and so on until the 100th row. Each glass holds one cup
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摘要：Given an array A, we may rotate it by a non-negative integer K so that the array becomes A[K], A[K+1], A{K+2], ... A[A.length - 1], A[0], A[1], ..., A
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摘要：Given a directed, acyclic graph of N nodes. Find all possible paths from node 0 to node N-1, and return them in any order. The graph is given as follo
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摘要：We 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,
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摘要：We are given an array A of positive integers, and two positive integers L and R (L <= R). Return the number of (contiguous, non-empty) subarrays such
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摘要：A Tic-Tac-Toe board is given as a string array board. Return True if and only if it is possible to reach this board position during the course of a va
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摘要：Let f(x) be the number of zeroes at the end of x!. (Recall that x! = 1 * 2 * 3 * ... * x, and by convention, 0! = 1.) For example, f(3) = 0 because 3!
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摘要：Given a string s and an array of strings words, return the number of words[i] that is a subsequence of s. A subsequence of a string is a new string ge
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摘要：S and T are strings composed of lowercase letters. In S, no letter occurs more than once. S was sorted in some custom order previously. We want to per
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摘要：You have two types of tiles: a 2 x 1 domino shape and a tromino shape. You may rotate these shapes. Given an integer n, return the number of ways to t
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