-
Notifications
You must be signed in to change notification settings - Fork 1
Expand file tree
/
Copy pathIslandPerimeter.java
More file actions
44 lines (39 loc) · 1.69 KB
/
IslandPerimeter.java
File metadata and controls
44 lines (39 loc) · 1.69 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
// You are given a map in form of a two-dimensional integer grid where 1 represents land and 0 represents water.
// Grid cells are connected horizontally/vertically (not diagonally). The grid is completely surrounded by water,
// and there is exactly one island (i.e., one or more connected land cells).
// The island doesn't have "lakes" (water inside that isn't connected to the water around the island).
// One cell is a square with side length 1. The grid is rectangular, width and height don't exceed 100.
// Determine the perimeter of the island.
// See: https://leetcode.com/problems/island-perimeter/
package leetcode.array_and_hashtable;
public class IslandPerimeter {
public int islandPerimeter(int[][] grid) {
int res = 0;
for (int i = 0; i < grid.length; i++) {
for (int j = 0; j < grid[0].length; j++) {
if (grid[i][j] == 0) continue;
int curr = 4;
if (i > 0 && grid[i - 1][j] == 1)
curr--;
if (i < grid.length - 1 && grid[i + 1][j] == 1)
curr--;
if (j > 0 && grid[i][j - 1] == 1)
curr--;
if (j < grid[0].length - 1 && grid[i][j + 1] == 1)
curr--;
res += curr;
}
}
return res;
}
public static void main(String[] args) {
IslandPerimeter sln = new IslandPerimeter();
System.out.println(sln.islandPerimeter(new int[][] {
{ 0, 1, 0, 0 },
{ 1, 1, 1, 0 },
{ 0, 1, 0, 0 },
{ 1, 1, 0, 0 }
}));
System.out.println(sln.islandPerimeter(new int[][] {{ 0, 1 }}));
}
}