240227 지형 이동

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

	while (!queue.isEmpty()) {
		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;
		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 || visited[nx][ny]) {
				continue;
			}

			int nextHeight = land[nx][ny];
			int heightDiff = Math.abs(nextHeight - currentHeight);

			if (heightDiff > height) {
				queue.add(new int[] { heightDiff, nx, ny });
			} else {
				queue.add(new int[] { 0, nx, ny });
			}
		}
	}
	return value;
}

출처:https://school.programmers.co.kr/learn/courses/30/lessons/62050