题目链接：Reverse Nodes in k-GroupGiven a linked list, reverse the nodes of a linked list k at a time and return its modified list.If the number of nodes is not a multiple ...
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题目链接：Swap Nodes in PairsGiven a linked list, swap every two adjacent nodes and return its head.For example,Given 1->2->3->4, you should return the list as 2-&...
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题目链接：Merge k Sorted ListsMerge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity.这道题的要求是将k个有序链表合并成1个有序链表，并分析其复杂度。 暴力合并 ...
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题目链接：Generate ParenthesesGiven n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.For example, given n = 3, a solution se...
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题目链接：Merge Two Sorted ListsMerge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists...
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题目链接：Valid ParenthesesGiven a string containing just the characters ‘(‘, ‘)’, ‘{‘, ‘}’, ‘[’ and ‘]’, determine if the input string is valid.The brackets must close in ...
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题目链接：Remove Nth Node From End of ListGiven a linked list, remove the nth node from the end of list and return its head.For example,Given linked list: 1->2->3->...
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题目链接：4SumGiven an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d = target? Find all unique quadruplets in the array which gives ...
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题目链接：Letter Combinations of a Phone NumberGiven a digit string, return all possible letter combinations that the number could represent.A mapping of digit to letters (...
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题目链接：3Sum ClosestGiven an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers....
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