随笔分类 - LeetCode
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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摘要：You are playing a simplified Pacman game. You start at the point (0, 0), and your destination is (target[0], target[1]). There are several ghosts on t
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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：A sorted list A contains 1, plus some number of primes. Then, for every p < q in the list, we consider the fraction p/q. What is the K-th smallest fra
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摘要：There are n cities connected by m flights. Each fight starts from city u and arrives at v with a price w. Now given all the cities and fights, togethe
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摘要：Given a string S, we can transform every letter individually to be lowercase or uppercase to create another string. Return a list of all possible stri
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摘要：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. Exa
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摘要：An N x N board contains only 0s and 1s. In each move, you can swap any 2 rows with each other, or any 2 columns with each other. What is the minimum n
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摘要：In a forest, each rabbit has some color. Some subset of rabbits (possibly all of them) tell you how many other rabbits have the same color as them. Th
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摘要：A move consists of taking a point (x, y) and transforming it to either (x, x+y) or (x+y, y). Given a starting point (sx, sy) and a target point (tx, t
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摘要：On the first row, we write a 0. Now in every subsequent row, we look at the previous row and replace each occurrence of 0 with 01, and each occurrence
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摘要：On an N x N grid, each square grid[i][j] represents the elevation at that point (i,j). Now rain starts to fall. At time t, the depth of the water ever
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摘要：In a string composed of 'L', 'R', and 'X' characters, like "RXXLRXRXL", a move consists of either replacing one occurrence of "XL" with "LX", or repla
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摘要：Given a Binary Search Tree (BST) with root node root, and a target value V, split the tree into two subtrees where one subtree has nodes that are all
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摘要：We have some permutation A of [0, 1, ..., N - 1], where N is the length of A. The number of (global) inversions is the number of i < j with 0 <= i < j
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摘要：On a horizontal number line, we have gas stations at positions stations[0], stations[1], ..., stations[N-1], where N = stations.length. Now, we add K
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摘要：On an 2 x 3 board, there are five tiles labeled from 1 to 5, and an empty square represented by 0. A move consists of choosing 0 and a 4-directionally
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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：You're given strings J representing the types of stones that are jewels, and S representing the stones you have. Each character in Sis a type of stone
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