Add Number of Islands

1 files changed, 38 insertions, 0 deletions

diff --git a/NumberOfIslands.java b/NumberOfIslands.java
new file mode 100644
index 0000000..422b80e
--- /dev/null
+++ b/NumberOfIslands.java
@@ -0,0 +1,38 @@
+import java.lang.*;
+import java.util.*;
+
+class NumberOfIslands {
+	public static void setZero(int y, int x, int[][] grid) {
+		if (y < 0 || y > grid.length - 1 || x < 0 || x > grid[0].length - 1 || grid[y][x] == 0)
+			return;
+		grid[y][x] = 0;
+		System.out.println("y: " + y + " x: " + x);
+		setZero(y, x + 1, grid);
+		setZero(y + 1, x, grid);
+		setZero(y, x - 1, grid);
+		setZero(y - 1, x, grid);
+	}
+
+	public static int numIslands(int[][] grid) {
+		int num = 0;
+		for (int y = 0; y < grid.length; y++) {
+			for (int x = 0; x < grid[y].length; x++) {
+				if (grid[y][x] == 1) {
+					num++;
+					setZero(y, x, grid);
+				}
+			}
+		}
+		return num;
+	}
+
+	public static void main(String[] args) {
+		int[][] grid = {
+		  {1,1,1,1,0},
+		  {1,1,0,1,0},
+		  {1,1,0,0,0},
+		  {0,0,0,1,1}
+		};
+		System.out.println(numIslands(grid));
+	}
+}