general bfs to fill the matrix

Author: Arjiit

BFS/floodFill.java

@@ -0,0 +1,35 @@
+class Point {
+    int x;
+    int y;
+    public Point(int x, int y) {
+        this.x = x;
+        this.y = y;
+    }
+}
+class Solution {
+    public int[][] floodFill(int[][] image, int sr, int sc, int newColor) {
+        int[][] dir = {{0,-1}, {-1,0}, {0,1}, {1,0}};
+        Queue<Point> q = new LinkedList<>();
+        Point newPoint = new Point(sr, sc);
+        int prevColor = image[sr][sc];
+        if (prevColor != newColor) {
+            q.add(newPoint);
+        }
+        while(!q.isEmpty()) {
+            int s = q.size();
+            for (int i=0; i<s; i++) {
+                Point poll = q.poll();
+                image[poll.x][poll.y] = newColor;
+                for (int[] d: dir) {
+                    Point new_point = new Point(d[0] + poll.x, d[1] + poll.y);
+                    if (new_point.x >= 0 && new_point.x < image.length && new_point.y >= 0 && new_point.y < image[0].length && image[new_point.x][new_point.y] == prevColor) {
+                        image[new_point.x][new_point.y] = 2;
+                        q.add(new_point);
+                    }
+                }
+            }
+        }
+        
+        return image;
+    }
+}