230314 지형 이동

public static int solution(int[][] land, int height) {
    int n = land.length;

    boolean[][] visited = new boolean[n][n];
    int[][] move = { { 1, 0 }, { 0, 1 }, { -1, 0 }, { 0, -1 } };

    PriorityQueue<int[]> queue = new PriorityQueue<>((a, b) -> a[0] - b[0]);

    int visitCount = 0;
    int maxCount = n * n;
    int value = 0;

    queue.offer(new int[] { 0, 0, 0 });

    while (visitCount < maxCount) {
        int[] curr = queue.poll();
        int val = curr[0];
        int x = curr[1];
        int y = curr[2];

        if (visited[x][y]) {
            continue;
        }
        visited[x][y] = true;

        visitCount++;
        value += val;

        int currentHeight = land[x][y];

        for (int[] d : move) {
            int nx = x + d[0];
            int ny = y + d[1];

            if (nx < 0 || ny < 0 || nx >= n || ny >= n) {
                continue;
            }

            int nextHeight = land[nx][ny];

            if (Math.abs(nextHeight - currentHeight) > height) {
                queue.add(new int[] { Math.abs(nextHeight - currentHeight), nx, ny });
            } else {
                queue.add(new int[] { 0, nx, ny });
            }
        }
    }
    return value;
}