Data commit

Task/Cut-a-rectangle/Groovy/cut-a-rectangle.groovy

@@ -0,0 +1,61 @@
+class CutRectangle {
+    private static int[][] dirs = [[0, -1], [-1, 0], [0, 1], [1, 0]]
+
+    static void main(String[] args) {
+        cutRectangle(2, 2)
+        cutRectangle(4, 3)
+    }
+
+    static void cutRectangle(int w, int h) {
+        if (w % 2 == 1 && h % 2 == 1) {
+            return
+        }
+
+        int[][] grid = new int[h][w]
+        Stack<Integer> stack = new Stack<>()
+
+        int half = (int) ((w * h) / 2)
+        long bits = (long) Math.pow(2, half) - 1
+
+        for (; bits > 0; bits -= 2) {
+            for (int i = 0; i < half; i++) {
+                int r = (int) (i / w)
+                int c = i % w
+                grid[r][c] = (bits & (1 << i)) != 0 ? 1 : 0
+                grid[h - r - 1][w - c - 1] = 1 - grid[r][c]
+            }
+
+            stack.push(0)
+            grid[0][0] = 2
+            int count = 1
+            while (!stack.empty()) {
+                int pos = stack.pop()
+                int r = (int) (pos / w)
+                int c = pos % w
+
+                for (int[] dir : dirs) {
+                    int nextR = r + dir[0]
+                    int nextC = c + dir[1]
+
+                    if (nextR >= 0 && nextR < h && nextC >= 0 && nextC < w) {
+                        if (grid[nextR][nextC] == 1) {
+                            stack.push(nextR * w + nextC)
+                            grid[nextR][nextC] = 2
+                            count++
+                        }
+                    }
+                }
+            }
+            if (count == half) {
+                printResult(grid)
+            }
+        }
+    }
+
+    static void printResult(int[][] arr) {
+        for (int[] a : arr) {
+            println(Arrays.toString(a))
+        }
+        println()
+    }
+}