Initial data commit

Task/Cut-a-rectangle/Java/cut-a-rectangle.java

@@ -0,0 +1,66 @@
+import java.util.*;
+
+public class CutRectangle {
+
+    private static int[][] dirs = {{0, -1}, {-1, 0}, {0, 1}, {1, 0}};
+
+    public 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 = (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 = 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 = 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)
+            System.out.println(Arrays.toString(a));
+        System.out.println();
+    }
+}