꿈꾸는공학도

https://leetcode.com/problems/merge-two-binary-trees/description/You are given two binary trees root1 and root2.Imagine that when you put one of them to cover the other, some nodes of the two trees are overlapped while the others are not. You need to merge the two trees into a new binary tree. The merge rule is that if two nodes overlap, then sum node values up as the new value of the merged nod..

# Definition for a binary tree node.# class TreeNode:# def __init__(self, val=0, left=None, right=None):# self.val = val# self.left = left# self.right = rightclass Solution: def levelOrder(self, root: Optional[TreeNode]) -> List[List[int]]: ans = [] self.dfs(root, ans, 0) return ans def dfs(self, node, ans, lv): if not node: ..

https://leetcode.com/problems/find-the-student-that-will-replace-the-chalk/description/?envType=daily-question&envId=2024-09-02There are n students in a class numbered from 0 to n - 1. The teacher will give each student a problem starting with the student number 0, then the student number 1, and so on until the teacher reaches the student number n - 1. After that, the teacher will restart the pr..

https://leetcode.com/problems/add-one-row-to-tree/?envType=daily-question&envId=2024-08-23Given the root of a binary tree and two integers val and depth, add a row of nodes with value val at the given depth depth.Note that the root node is at depth 1.The adding rule is:Given the integer depth, for each not null tree node cur at the depth depth - 1, create two tree nodes with value val as cur's l..

https://leetcode.com/problems/fraction-addition-and-subtraction/description/?envType=daily-question&envId=2024-08-23Given a string expression representing an expression of fraction addition and subtraction, return the calculation result in string format.The final result should be an irreducible fraction. If your final result is an integer, change it to the format of a fraction that has a denomin..

https://leetcode.com/problems/sqrtx/description/Given a non-negative integer x, return the square root of x rounded down to the nearest integer. The returned integer should be non-negative as well.You must not use any built-in exponent function or operator.For example, do not use pow(x, 0.5) in c++ or x ** 0.5 in python. Example 1:Input: x = 4Output: 2Explanation: The square root of 4 is 2, so w..

https://leetcode.com/problems/maximum-width-of-binary-tree/description/Given the root of a binary tree, return the maximum width of the given tree.The maximum width of a tree is the maximum width among all levels.The width of one level is defined as the length between the end-nodes (the leftmost and rightmost non-null nodes), where the null nodes between the end-nodes that would be present in a ..

https://leetcode.com/problems/same-tree/description/Given the roots of two binary trees p and q, write a function to check if they are the same or not.Two binary trees are considered the same if they are structurally identical, and the nodes have the same value. Example 1:Input: p = [1,2,3], q = [1,2,3]Output: trueExample 2:Input: p = [1,2], q = [1,null,2]Output: falseExample 3:Input: p = [1,2,1..

첨부파일의 코드에는 필자가 직접 연습한 것과 약간의 낙서(?)가 가미되어 있다ㅎㅎ   C에는 Python / C++의 Class와 유사하게 Struct라는 구조가 있다. 이 Struct는 Array보단 고차원의 구조로, 각 종 data type 또는 다른 Sturct type의 Variable을 member로 가질 수 있다. 하지만, fucntion을 Member 변수로 갖지 못하고 Class 상속 / Polymorphism, Instance Construct/Destruct 등 객체지향프로그래밍 즉 Oriented Object Programming을 실행하기엔 부족함이 많다. 그래도 보수적인 C Programming 영역에서 가장 고차원적인 구조이기에 연습이 필요하다. Q1.  첫 번째론 좌표평면 상에..

https://leetcode.com/problems/repeated-substring-pattern/description/Given a string s, check if it can be constructed by taking a substring of it and appending multiple copies of the substring together. Example 1:Input: s = "abab"Output: trueExplanation: It is the substring "ab" twice.Example 2:Input: s = "aba"Output: falseExample 3:Input: s = "abcabcabcabc"Output: trueExplanation: It is the sub..