程序師世界是廣大編程愛好者互助、分享、學習的平台,程序師世界有你更精彩!
首頁
編程語言
C語言|JAVA編程
Python編程
網頁編程
ASP編程|PHP編程
JSP編程
數據庫知識
MYSQL數據庫|SqlServer數據庫
Oracle數據庫|DB2數據庫
 程式師世界 >> 編程語言 >> C語言 >> C++ >> 關於C++ >> leetcode 218: The Skyline Problem

leetcode 218: The Skyline Problem

編輯:關於C++

The Skyline Problem

Total Accepted: 1071 Total Submissions: 6525

A city's skyline is the outer contour of the silhouette formed by all the buildings in that city when viewed from a distance. Now suppose you aregiven the locations and height of all the buildings as shown on a cityscape photo (Figure A), write a program tooutput the skyline formed by these buildings collectively (Figure B).

BuildingsSkyline Contour

The geometric information of each building is represented by a triplet of integers[Li, Ri, Hi], where Li and Ri are the x coordinates of the left and right edge of the ith building, respectively, andHi is its height. It is guaranteed that 0 ≤ Li, Ri ≤ INT_MAX,0 < Hi ≤ INT_MAX, and Ri - Li > 0. You may assume all buildings are perfect rectangles grounded on an absolutely flat surface at height 0.

For instance, the dimensions of all buildings in Figure A are recorded as: [ [2 9 10], [3 7 15], [5 12 12], [15 20 10], [19 24 8] ] .

The output is a list of "key points" (red dots in Figure B) in the format of[ [x1,y1], [x2, y2], [x3, y3], ... ] that uniquely defines a skyline.A key point is the left endpoint of a horizontal line segment. Note that the last key point, where the rightmost building ends, is merely used to mark the termination of the skyline, and always has zero height. Also, the ground in between any two adjacent buildings should be considered part of the skyline contour.

For instance, the skyline in Figure B should be represented as:[ [2 10], [3 15], [7 12], [12 0], [15 10], [20 8], [24, 0] ].

Notes:

The number of buildings in any input list is guaranteed to be in the range [0, 10000].The input list is already sorted in ascending order by the left x position Li. The output list must be sorted by the x position. 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], ...]

[思路]

起床再寫 : )

[CODE]

 

public class Solution {
    public List getSkyline(int[][] buildings) {
        List res = new ArrayList();
        PriorityQueue maxHeap = new PriorityQueue(11, new Comparator(){
            @Override
            public int compare(Integer a, Integer b) {
                return b - a;
            }
        });
        List bl = new ArrayList();
        for(int i=0; i() {
        	@Override
			public int compare(int[] a, int[] b) {
        		if(a[0]!=b[0]) return a[0] - b[0];
        		else return b[1] - a[1];
        	}
        });
        int pre = 0, cur = 0;
        for(int i=0; i0) {
                maxHeap.add(b[1]);
                cur = maxHeap.peek();
            } else {
                maxHeap.remove(-b[1]);
                cur = (maxHeap.peek()==null) ? 0 : maxHeap.peek();
            }
            if(cur!=pre) {
                res.add(new int[]{b[0], cur});
                pre = cur;
            }
        }		
        return res;		
    }
}


 

  1. 上一頁:
  2. 下一頁:
Copyright © 程式師世界 All Rights Reserved