0802 Find Eventual Safe States

Question

My Solution:

class Solution {
    public List<Integer> eventualSafeNodes(int[][] graph) {
        List<Integer> res = new ArrayList<>();
        int[] visited = new int[graph.length];
        
        for(int i = 0; i < graph.length; i++){
            if(isSafe(i, graph, visited)){
                res.add(i);
            }
        }
        
        return res;
    }
    
    private boolean isSafe(int index, int[][] graph, int[] visited){
        if(visited[index] == 2){
            return true;
        }
        
        if(visited[index] == 1){
            return false;
        }
        
        visited[index] = 1;
        int[] neighbor = graph[index];
        
        for(int i = 0; i < neighbor.length; i++){
            if(!isSafe(neighbor[i], graph, visited)){
                return false;
            }
        }
        
        
        visited[index] = 2;
        return true;
    }
}