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The lowest common ancestor (LCA) of two nodes U and V in a tree is the deepest node that has both U and V as descendants. A binary search tree (BST) i 阅读全文
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Werewolf（狼人杀） is a game in which the players are partitioned into two parties: the werewolves and the human beings. Suppose that in a game, player #1 阅读全文
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Among all the factors of a positive integer N, there may exist several consecutive numbers. For example, 630 can be factored as 3×\times×5×\times×6×\t 阅读全文
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Eva would like to make a string of beads with her favorite colors so she went to a small shop to buy some beads. There were many colorful strings of b 阅读全文
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For two rational numbers, your task is to implement the basic arithmetics, that is, to calculate their sum, difference, product and quotient. Input Sp 阅读全文
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On a broken keyboard, some of the keys are worn out. So when you type some sentences, the characters corresponding to those keys will not appear on sc 阅读全文
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Given N rational numbers in the form numerator/denominator, you are supposed to calculate their sum. Input Specification: Each input file contains one 阅读全文
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The Japanese language is notorious for its sentence ending particles. Personal preference of such particles can be considered as a reflection of the s 阅读全文
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Scientific notation is the way that scientists easily handle very large numbers or very small numbers. The notation matches the regular expression [+- 阅读全文
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For any 4-digit integer except the ones with all the digits being the same, if we sort the digits in non-increasing order first, and then in non-decre 阅读全文
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Given three integers A, B and C in [−263,263], you are supposed to tell whether A+B>C. Input Specification: The first line of the input gives th 阅读全文
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Sherlock Holmes received a note with some strange strings: Let's date! 3485djDkxh4hhGE 2984akDfkkkkggEdsb s&hgsfdk d&Hyscvnm. It took him only a minut 阅读全文
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Behind the scenes in the computer's memory, color is always talked about as a series of 24 bits of information for each pixel. In an image, the color 阅读全文
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If you are a fan of Harry Potter, you would know the world of magic has its own currency system -- as Hagrid explained it to Harry, "Seventeen silver 阅读全文
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Given two strings S1 and S2, S=S1−S2 is defined to be the remaining string after taking all the characters in S2 from S1. Your task 阅读全文
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The task is really simple: given N exits on a highway which forms a simple cycle, you are supposed to tell the shortest distance between any pair of e 阅读全文
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Shuffling is a procedure used to randomize a deck of playing cards. Because standard shuffling techniques are seen as weak, and in order to avoid "ins 阅读全文
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Being unique is so important to people on Mars that even their lottery is designed in a unique way. The rule of winning is simple: one bets on a numbe 阅读全文
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Given any string of N (≥5) characters, you are asked to form the characters into the shape of U. For example, helloworld can be printed as: That is, t 阅读全文
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People in Mars represent the colors in their computers in a similar way as the Earth people. That is, a color is represented by a 6-digit number, wher 阅读全文