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

62 lines
1.7 KiB
Groovy

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()
}
}