꿈꾸는공학도

https://leetcode.com/problems/word-search/description/Given an m x n grid of characters board and a string word, return true if word exists in the grid.The word can be constructed from letters of sequentially adjacent cells, where adjacent cells are horizontally or vertically neighboring. The same letter cell may not be used more than once. Example 1:Input: board = [["A","B","C","E"],["S","F","C..

https://leetcode.com/problems/trapping-rain-water/description/Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it can trap after raining. Example 1:Input: height = [0,1,0,2,1,0,1,3,2,1,2,1]Output: 6Explanation: The above elevation map (black section) is represented by array [0,1,0,2,1,0,1,3,2,1,2,1]. In this case, 6 units of rai..

list of list[int] 의 data type을 받아서 가장 긴 connected 1's length를 반환하는 함수를 만들어야 한다. Matrix 는 2차원이다보니까 m*n Matrix를 생각하면 되고, 주어진 2차원 Matrix에서 어떤 것을 0에서 1로 바꿀 지 잘 고민해야하고 x, y축 index 헷갈리지 않게 주의해야 한다. 이거때문에 index overflow로 애좀 먹음.. 꿀팁은 python deque만 있으면 queue / stack 다 구현할 수 있다는 것이고, python의 경우 if 문에서 0  그리고 맨 처음 언급했듯이, x / y축 len과 idx following을 잘 해야 한다. 이런 종류의 문제는 무작정 coding에 들어가지 말고, 머릿속으로 또는 빈 종이에 구조를..

https://leetcode.com/problems/find-minimum-in-rotated-sorted-array-ii/description/Suppose an array of length n sorted in ascending order is rotated between 1 and n times. For example, the array nums = [0,1,4,4,5,6,7] might become:[4,5,6,7,0,1,4] if it was rotated 4 times.[0,1,4,4,5,6,7] if it was rotated 7 times.Notice that rotating an array [a[0], a[1], a[2], ..., a[n-1]] 1 time results in the ..

https://leetcode.com/problems/min-stack/description/Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.Implement the MinStack class:MinStack() initializes the stack object.void push(int val) pushes the element val onto the stack.void pop() removes the element on the top of the stack.int top() gets the top element of the stack.int getMin() retrieves t..

https://leetcode.com/problems/kth-smallest-element-in-a-bst/description/Given the root of a binary search tree, and an integer k, return the kth smallest value (1-indexed) of all the values of the nodes in the tree. Example 1:Input: root = [3,1,4,null,2], k = 1Output: 1Example 2:Input: root = [5,3,6,2,4,null,null,1], k = 3Output: 3 Constraints:The number of nodes in the tree is n.1 0 Follow up: ..

https://app.codility.com/programmers/lessons/9-maximum_slice_problem/max_profit/ MaxProfit coding task - Learn to Code - CodilityGiven a log of stock prices compute the maximum possible earning.app.codility.comAn array A consisting of N integers is given. It contains daily prices of a stock share for a period of N consecutive days. If a single share was bought on day P and sold on day Q, where 0..

https://leetcode.com/problems/maximum-depth-of-n-ary-tree/description/?envType=problem-list-v2&envId=treeGiven a n-ary tree, find its maximum depth.The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.Nary-Tree input serialization is represented in their level order traversal, each group of children is separated by the null value (See ..

https://leetcode.com/problems/is-graph-bipartite/description/?envType=problem-list-v2&envId=graphThere is an undirected graph with n nodes, where each node is numbered between 0 and n - 1. You are given a 2D array graph, where graph[u] is an array of nodes that node u is adjacent to. More formally, for each v in graph[u], there is an undirected edge between node u and node v. The graph has the f..

https://leetcode.com/problems/find-if-path-exists-in-graph/description/?envType=problem-list-v2&envId=graphThere is a bi-directional graph with n vertices, where each vertex is labeled from 0 to n - 1 (inclusive). The edges in the graph are represented as a 2D integer array edges, where each edges[i] = [ui, vi] denotes a bi-directional edge between vertex ui and vertex vi. Every vertex pair is c..