Package g0201_0300.s0218_the_skyline_problem

Class Solution

java.lang.Object

g0201_0300.s0218_the_skyline_problem.Solution

public class Solution
extends Object

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 is the x coordinate of the left edge of the ith building. * righti is the x coordinate of the right edge of the ith building. * heighti is the height of the ith building. You may assume all buildings are perfect rectangles grounded on an absolutely flat surface at height `0`. The **skyline** should be represented as a list of "key points" **sorted by their x-coordinate** in the form [[x1,y1],[x2,y2],...]. Each key point is the left endpoint of some horizontal segment in the skyline except the last point in the list, which always has a y-coordinate `0` and is used to mark the skyline's termination where the rightmost building ends. Any ground between the leftmost and rightmost buildings should be part of the skyline's contour. **Note:** There must be no consecutive horizontal lines of equal height in the output skyline. For instance, `[...,[2 3],[4 5],[7 5],[11 5],[12 7],...]` is not acceptable; the three lines of height 5 should be merged into one in the final output as such: `[...,[2 3],[4 5],[12 7],...]` **Example 1:**  **Input:** buildings = \[\[2,9,10],[3,7,15],[5,12,12],[15,20,10],[19,24,8]] **Output:** [[2,10],[3,15],[7,12],[12,0],[15,10],[20,8],[24,0]] **Explanation:** Figure A shows the buildings of the input. Figure B shows the skyline formed by those buildings. The red points in figure B represent the key points in the output list. **Example 2:** **Input:** buildings = \[\[0,2,3],[2,5,3]] **Output:** [[0,3],[5,0]] **Constraints:** * 1 <= buildings.length <= 104 * 0 <= lefti < righti <= 231 - 1 * 1 <= heighti <= 231 - 1 * `buildings` is sorted by lefti in non-decreasing order.

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
List<List<Integer>>	getSkyline(int[][] buildings)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Solution

public Solution()

Method Details

getSkyline

public List<List<Integer>> getSkyline(int[][] buildings)