mjk study log

문제Given an encoded string, return its decoded string.The encoding rule is: k[encoded_string], where the encoded_string inside the square brackets is being repeated exactly k times. Note that k is guaranteed to be a positive integer.You may assume that the input string is always valid; there are no extra white spaces, square brackets are well-formed, etc. Furthermore, you may assume that the orig..

문제Given the head of a singly linked list, group all the nodes with odd indices together followed by the nodes with even indices, and return the reordered list.The first node is considered odd, and the second node is even, and so on.Note that the relative order inside both the even and odd groups should remain as it was in the input.You must solve the problem in O(1) extra space complexity and O(..

문제Given an integer array nums, rotate the array to the right by k steps, where k is non-negative. Example 1:Input: nums = [1,2,3,4,5,6,7], k = 3 Output: [5,6,7,1,2,3,4] Explanation: rotate 1 steps to the right: [7,1,2,3,4,5,6] rotate 2 steps to the right: [6,7,1,2,3,4,5] rotate 3 steps to the right: [5,6,7,1,2,3,4] Example 2:Input: nums = [-1,-100,3,99], k = 2 Output: [3,99,-1,-100] Explanation:..

문제Given an unsorted array of integers nums, return the length of the longest consecutive elements sequence.You must write an algorithm that runs in O(n) time. Example 1:Input: nums = [100,4,200,1,3,2]Output: 4Explanation: The longest consecutive elements sequence is [1, 2, 3, 4]. Therefore its length is 4.Example 2:Input: nums = [0,3,7,2,5,8,4,6,0,1]Output: 9Example 3:Input: nums = [1,0,1,2]Outp..

문제 Given strings s1, s2, and s3, find whether s3 is formed by an interleaving of s1 and s2.An interleaving of two strings s and t is a configuration where s and t are divided into n and m substrings respectively, such that:s = s1 + s2 + ... + snt = t1 + t2 + ... + tm|n - m| The interleaving is s1 + t1 + s2 + t2 + s3 + t3 + ... or t1 + s1 + t2 + s2 + t3 + s3 + ...Note: a + b is the concatenation ..

문제You are given the head of a linked list with n nodes.For each node in the list, find the value of the next greater node. That is, for each node, find the value of the first node that is next to it and has a strictly larger value than it.Return an integer array answer where answer[i] is the value of the next greater node of the ith node (1-indexed). If the ith node does not have a next greater ..