컴퓨터공학/LeetCode 1000

[LeetCode] 531. Lonely Pixel I

531. Lonely Pixel I Medium Given an m x n picture consisting of black 'B' and white 'W' pixels, return the number of black lonely pixels. A black lonely pixel is a character 'B' that located at a specific position where the same row and same column don't have any other black pixels. Example 1: Input: picture = [["W","W","B"],["W","B","W"],["B","W","W"]] Output: 3 Explanation: All the three 'B's ..

[LeetCode] 1578. Minimum Time to Make Rope Colorful

1578. Minimum Time to Make Rope Colorful Medium Alice has n balloons arranged on a rope. You are given a 0-indexed string colors where colors[i] is the color of the ith balloon. Alice wants the rope to be colorful. She does not want two consecutive balloons to be of the same color, so she asks Bob for help. Bob can remove some balloons from the rope to make it colorful. You are given a 0-indexed..

[LeetCode] 1155. Number of Dice Rolls With Target Sum

1155. Number of Dice Rolls With Target Sum Medium You have n dice and each die has k faces numbered from 1 to k. Given three integers n, k, and target, return the number of possible ways (out of the kn total ways) to roll the dice so the sum of the face-up numbers equals target. Since the answer may be too large, return it modulo 109 + 7. Example 1: Input: n = 1, k = 6, target = 3 Output: 1 Expl..

[LeetCode] 91. Decode Ways

91. Decode Ways Medium A message containing letters from A-Z can be encoded into numbers using the following mapping: 'A' -> "1" 'B' -> "2" ... 'Z' -> "26" To decode an encoded message, all the digits must be grouped then mapped back into letters using the reverse of the mapping above (there may be multiple ways). For example, "11106" can be mapped into: "AAJF" with the grouping (1 1 10 6) "KJF"..

[LeetCode] 218. The Skyline Problem

218. The Skyline Problem Hard A city's skyline is the outer contour of the silhouette formed by all the buildings in that city when viewed from a distance. Given the locations and heights of all the buildings, return the skyline formed by these buildings collectively. The geometric information of each building is given in the array buildings where buildings[i] = [lefti, righti, heighti]: lefti i..

[LeetCode] 658. Find K Closest Elements

658. Find K Closest Elements Medium Given a sorted integer array arr, two integers k and x, return the k closest integers to x in the array. The result should also be sorted in ascending order. An integer a is closer to x than an integer b if: |a - x| < |b - x|, or |a - x| == |b - x| and a < b Example 1: Input: arr = [1,2,3,4,5], k = 4, x = 3 Output: [1,2,3,4] Example 2: Input: arr = [1,2,3,4,5]..

[LeetCode] 967. Numbers With Same Consecutive Differences

967. Numbers With Same Consecutive Differences Medium Given two integers n and k, return an array of all the integers of length n where the difference between every two consecutive digits is k. You may return the answer in any order. Note that the integers should not have leading zeros. Integers as 02 and 043 are not allowed. Example 1: Input: n = 3, k = 7 Output: [181,292,707,818,929] Explanati..

[LeetCode] 19. Remove Nth Node From End of List

19. Remove Nth Node From End of List Medium Given the head of a linked list, remove the nth node from the end of the list and return its head. Example 1: Input: head = [1,2,3,4,5], n = 2 Output: [1,2,3,5] Example 2: Input: head = [1], n = 1 Output: [] Example 3: Input: head = [1,2], n = 1 Output: [1] Constraints: The number of nodes in the list is sz. 1