lintcode 443 岛屿数量问题

src/test/java/com/ossez/lang/tutorial/tests/lintcode/LintCode0433NumIslandsTest.java

@@ -0,0 +1,94 @@
+package com.ossez.lang.tutorial.tests.lintcode;
+
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * <p>
+ * 433
+ * <ul>
+ * <li>@see <a href=
+ * "https://www.cwiki.us/display/ITCLASSIFICATION/Number+of+Islands">https://www.cwiki.us/display/ITCLASSIFICATION/Number+of+Islands</a>
+ * <li>@see<a href="https://www.lintcode.com/problem/number-of-islands/">https://www.lintcode.com/problem/number-of-islands/</a>
+ * </ul>
+ * </p>
+ * 
+ * @author YuCheng
+ *
+ */
+public class LintCode0433NumIslandsTest {
+
+	private final static Logger logger = LoggerFactory.getLogger(LintCode0433NumIslandsTest.class);
+
+	/**
+	 * 
+	 */
+	@Test
+	public void testMain() {
+		logger.debug("BEGIN");
+		// INIT GRID
+		boolean[][] grid = { { true, true, false, false, false }, { false, true, false, false, true }, { false, false, false, true, true },
+				{ false, false, false, false, false }, { false, false, false, false, true }
+
+		};
+
+		// NULL CHECK
+		if (grid.length == 0 || grid[0].length == 0) {
+			System.out.println("NULL");
+			// return 0;
+		}
+
+		// GET SIZE
+		int n = grid.length;
+		int m = grid[0].length;
+
+		// ARRAY FOR VISITED LOG
+		boolean[][] visited = new boolean[n][m];
+
+		int count = 0;
+
+		// LOOP FOR GRID
+		for (int i = 0; i < n; i++) {
+			for (int j = 0; j < m; j++) {
+				if (grid[i][j] && !visited[i][j]) {
+					numIslandsDFS(grid, visited, i, j);
+					count++;
+				}
+			}
+		}
+
+		System.out.println(count);
+
+	}
+
+	/**
+	 * 
+	 * @param grid
+	 * @param visited
+	 * @param x
+	 * @param y
+	 */
+	public void numIslandsDFS(boolean[][] grid, boolean[][] visited, int x, int y) {
+		if (x < 0 || x >= grid.length) {
+			return;
+		}
+
+		if (y < 0 || y >= grid[0].length) {
+			return;
+		}
+
+		if (grid[x][y] != true || visited[x][y]) {
+			return;
+		}
+
+		visited[x][y] = true;
+
+		// Recursive call
+		numIslandsDFS(grid, visited, x - 1, y);
+		numIslandsDFS(grid, visited, x + 1, y);
+		numIslandsDFS(grid, visited, x, y - 1);
+		numIslandsDFS(grid, visited, x, y + 1);
+
+	}
+}