private static void dfsCycle(ArrayList<int[]> cycleVertexAndSize, char[][] map, int x, int y, boolean[][] visited, boolean[][] onStack, ArrayDeque<int[]> stack) {
        visited[x][y] = true;
        onStack[x][y] = true;
        int[] ar = {x, y};
        stack.push(ar);
        ar = null;

        int nextX;
        int nextY;
        if (map[x][y] == 'R') {
            nextX = x;
            nextY = y + 1;
        } else if (map[x][y] == 'L') {
            nextX = x;
            nextY = y - 1;
        } else if (map[x][y] == 'U') {
            nextX = x - 1;
            nextY = y;
        } else {
            nextX = x + 1;
            nextY = y;
        }

        if (!visited[nextX][nextY]) {
            dfsCycle(cycleVertexAndSize, map, nextX ,nextY, visited, onStack, stack);
        } else {
            if (onStack[nextX][nextY]) {
                int circleSize = 1;
                while (!(stack.peek()[0] == nextX && stack.peek()[1] == nextY)) {
                    stack.pop();
                    circleSize++;
                }

                int[] vertexAndSize = new int[3];
                vertexAndSize[0] = nextX;
                vertexAndSize[1] = nextY;
                vertexAndSize[2] = circleSize;
                cycleVertexAndSize.add(vertexAndSize);
                vertexAndSize = null;
            }
        }

        if (!stack.isEmpty() && stack.peek()[0] == x && stack.peek()[1] == y) {
            stack.pop();
        }
        onStack[x][y] = false;
    }
}