Update Solution2.java #3110

Original file line number	Diff line number	Diff line change
		@@ -1,39 +1,32 @@
		class Solution {
	private char[][] grid;
	private int m;
	private int n;
	public int[] findOrder(int numCourses, int[][] prerequisites) {
	List<Integer>[] graph = new List[numCourses];
	int[] inDegrees = new int[numCourses];

	public int numIslands(char[][] grid) {
	m = grid.length;
	n = grid[0].length;
	this.grid = grid;
	int ans = 0;
	for (int i = 0; i < m; ++i) {
	for (int j = 0; j < n; ++j) {
	if (grid[i][j] == '1') {
	bfs(i, j);
	++ans;
	}
	}
	}
	return ans;
	for (int i = 0; i < numCourses; ++i)
	graph[i] = new ArrayList<>();

	for (int[] prerequisite : prerequisites) {
	graph[prerequisite[1]].add(prerequisite[0]);
	++inDegrees[prerequisite[0]];
		}

	private void bfs(int i, int j) {
	grid[i][j] = '0';
	Deque<int[]> q = new ArrayDeque<>();
	q.offer(new int[] {i, j});
	int[] dirs = {-1, 0, 1, 0, -1};
	while (!q.isEmpty()) {
	int[] p = q.poll();
	for (int k = 0; k < 4; ++k) {
	int x = p[0] + dirs[k];
	int y = p[1] + dirs[k + 1];
	if (x >= 0 && x < m && y >= 0 && y < n && grid[x][y] == '1') {
	q.offer(new int[] {x, y});
	grid[x][y] = '0';
	}
	}
	}
	int[] ans = new int[numCourses];
	int index = 0;

	Queue<Integer> q = new LinkedList<>();
	for (int i = 0; i < numCourses; ++i)
	if (inDegrees[i] == 0)
	q.offer(i);

	while (!q.isEmpty()) {
	int u = q.poll();
	ans[index++] = u;
	for (int v : graph[u])
	if (--inDegrees[v] == 0)
	q.offer(v);
		}
	}

	return index == numCourses ? ans : new int[] {};
	}
	}

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