2022-07-11 update: added "Flood Fill" (#30)

Author: fartem

Diff for: src/main/java/com/smlnskgmail/jaman/leetcodejava/easy/FloodFill.java

@@ -0,0 +1,44 @@
+package com.smlnskgmail.jaman.leetcodejava.easy;
+
+// https://leetcode.com/problems/flood-fill/
+public class FloodFill {
+
+    private final int[][] image;
+    private final int sr;
+    private final int sc;
+    private final int color;
+
+    public FloodFill(int[][] image, int sr, int sc, int color) {
+        this.image = image;
+        this.sr = sr;
+        this.sc = sc;
+        this.color = color;
+    }
+
+    public int[][] solution() {
+        int c = image[sr][sc];
+        if (c != color) {
+            dfs(image, sr, sc, c, color);
+        }
+        return image;
+    }
+
+    private void dfs(int[][] image, int r, int c, int color, int newColor) {
+        if (image[r][c] == color) {
+            image[r][c] = newColor;
+            if (r >= 1) {
+                dfs(image, r - 1, c, color, newColor);
+            }
+            if (c >= 1) {
+                dfs(image, r, c - 1, color, newColor);
+            }
+            if (r + 1 < image.length) {
+                dfs(image, r + 1, c, color, newColor);
+            }
+            if (c + 1 < image[0].length) {
+                dfs(image, r, c + 1, color, newColor);
+            }
+        }
+    }
+
+}

Diff for: src/test/java/com/smlnskgmail/jaman/leetcodejava/easy/FloodFillTest.java

@@ -0,0 +1,25 @@
+package com.smlnskgmail.jaman.leetcodejava.easy;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+
+public class FloodFillTest {
+
+    @Test
+    public void defaultTest() {
+        int[][] correct = new int[][]{{2, 2, 2}, {2, 2, 0}, {2, 0, 1}};
+        int[][] solution = new FloodFill(
+                new int[][]{{1, 1, 1}, {1, 1, 0}, {1, 0, 1}},
+                1,
+                1,
+                2
+        ).solution();
+        assertEquals(correct.length, solution.length);
+        for (int i = 0; i < correct.length; i++) {
+            assertArrayEquals(correct[i], solution[i]);
+        }
+    }
+
+}