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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 阅读全文
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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 阅读全文
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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] 阅读全文
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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 阅读全文
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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 阅读全文
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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 阅读全文
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Give a string s, count the number of non-empty (contiguous) substrings that have the same number of 0's and 1's, and all the 0's and all the 1's in th 阅读全文
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Given a string representing a code snippet, you need to implement a tag validator to parse the code and return whether it is valid. A code snippet is 阅读全文
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Given two words word1 and word2, find the minimum number of steps required to make word1 and word2 the same, where in each step you can delete one cha 阅读全文
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Given an integer n, find the closest integer (not including itself), which is a palindrome. The 'closest' is defined as absolute difference minimized 阅读全文