Feature iterative flood fill (#6584)

* feat: FloodFill Algorithm with iterative approach - nested class Point: helper class, represents point in 2D field (x,y) - shouldSkipPixel method: helper method to validate point - floodFill method: iterative version of floodFill, uses Queue to add and poll Points and change it color if allowed * feat: tests for IterativeFloodFill -same tests as for normal floodFill and test for a big image * docs: add link to floodFill algorithm * codeStyle fix * tests: add tests for edge cases * codeStyle fix * codeStyle fix * codeStyle fix * refactor: reorganize structure and add JavaDoc - Move private methods after public methods for better readability - Add class-level JavaDoc documentation with algorithm description and links to references
2025-12-19 07:00:35 +08:00 · 2025-10-09 20:20:19 +03:00
parent b1aa896e17
commit 16557a9b81
2 changed files with 265 additions and 0 deletions
--- a/src/test/java/com/thealgorithms/others/IterativeFloodFillTest.java
+++ b/src/test/java/com/thealgorithms/others/IterativeFloodFillTest.java
@@ -0,0 +1,163 @@
+package com.thealgorithms.others;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+
+import org.junit.jupiter.api.Test;
+
+class IterativeFloodFillTest {
+
+    @Test
+    void testForEmptyImage() {
+        int[][] image = {};
+        int[][] expected = {};
+
+        IterativeFloodFill.floodFill(image, 4, 5, 3, 2);
+        assertArrayEquals(expected, image);
+    }
+
+    @Test
+    void testForSingleElementImage() {
+        int[][] image = {{1}};
+        int[][] expected = {{3}};
+
+        IterativeFloodFill.floodFill(image, 0, 0, 3, 1);
+        assertArrayEquals(expected, image);
+    }
+
+    @Test
+    void testForEmptyRow() {
+        int[][] image = {{}};
+        int[][] expected = {{}};
+
+        IterativeFloodFill.floodFill(image, 4, 5, 3, 2);
+        assertArrayEquals(expected, image);
+    }
+
+    @Test
+    void testForImageOne() {
+        int[][] image = {
+            {0, 0, 0, 0, 0, 0, 0},
+            {0, 3, 3, 3, 3, 0, 0},
+            {0, 3, 1, 1, 5, 0, 0},
+            {0, 3, 1, 1, 5, 5, 3},
+            {0, 3, 5, 5, 1, 1, 3},
+            {0, 0, 0, 5, 1, 1, 3},
+            {0, 0, 0, 3, 3, 3, 3},
+        };
+
+        int[][] expected = {
+            {0, 0, 0, 0, 0, 0, 0},
+            {0, 3, 3, 3, 3, 0, 0},
+            {0, 3, 2, 2, 5, 0, 0},
+            {0, 3, 2, 2, 5, 5, 3},
+            {0, 3, 5, 5, 2, 2, 3},
+            {0, 0, 0, 5, 2, 2, 3},
+            {0, 0, 0, 3, 3, 3, 3},
+        };
+
+        IterativeFloodFill.floodFill(image, 2, 2, 2, 1);
+        assertArrayEquals(expected, image);
+    }
+
+    @Test
+    void testForImageTwo() {
+        int[][] image = {
+            {0, 0, 1, 1, 0, 0, 0},
+            {1, 1, 3, 3, 3, 0, 0},
+            {1, 3, 1, 1, 5, 0, 0},
+            {0, 3, 1, 1, 5, 5, 3},
+            {0, 3, 5, 5, 1, 1, 3},
+            {0, 0, 0, 5, 1, 1, 3},
+            {0, 0, 0, 1, 3, 1, 3},
+        };
+
+        int[][] expected = {
+            {0, 0, 2, 2, 0, 0, 0},
+            {2, 2, 3, 3, 3, 0, 0},
+            {2, 3, 2, 2, 5, 0, 0},
+            {0, 3, 2, 2, 5, 5, 3},
+            {0, 3, 5, 5, 2, 2, 3},
+            {0, 0, 0, 5, 2, 2, 3},
+            {0, 0, 0, 2, 3, 2, 3},
+        };
+
+        IterativeFloodFill.floodFill(image, 2, 2, 2, 1);
+        assertArrayEquals(expected, image);
+    }
+
+    @Test
+    void testForImageThree() {
+        int[][] image = {
+            {1, 1, 2, 3, 1, 1, 1},
+            {1, 0, 0, 1, 0, 0, 1},
+            {1, 1, 1, 0, 3, 1, 2},
+        };
+
+        int[][] expected = {
+            {4, 4, 2, 3, 4, 4, 4},
+            {4, 0, 0, 4, 0, 0, 4},
+            {4, 4, 4, 0, 3, 4, 2},
+        };
+
+        IterativeFloodFill.floodFill(image, 0, 1, 4, 1);
+        assertArrayEquals(expected, image);
+    }
+
+    @Test
+    void testForSameNewAndOldColor() {
+        int[][] image = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        int[][] expected = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        IterativeFloodFill.floodFill(image, 0, 1, 1, 1);
+        assertArrayEquals(expected, image);
+    }
+
+    @Test
+    void testForBigImage() {
+        int[][] image = new int[100][100];
+
+        assertDoesNotThrow(() -> IterativeFloodFill.floodFill(image, 0, 0, 1, 0));
+    }
+
+    @Test
+    void testForBelowZeroX() {
+        int[][] image = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        int[][] expected = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        IterativeFloodFill.floodFill(image, -1, 1, 1, 0);
+        assertArrayEquals(expected, image);
+    }
+
+    @Test
+    void testForBelowZeroY() {
+        int[][] image = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        int[][] expected = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        IterativeFloodFill.floodFill(image, 1, -1, 1, 0);
+        assertArrayEquals(expected, image);
+    }
+
+    @Test
+    void testForAboveBoundaryX() {
+        int[][] image = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        int[][] expected = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        IterativeFloodFill.floodFill(image, 100, 1, 1, 0);
+        assertArrayEquals(expected, image);
+    }
+
+    @Test
+    void testForAboveBoundaryY() {
+        int[][] image = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        int[][] expected = {{1, 1, 2}, {1, 0, 0}, {1, 1, 1}};
+
+        IterativeFloodFill.floodFill(image, 1, 100, 1, 0);
+        assertArrayEquals(expected, image);
+    }
+}