原题链接：Leetcode 841. 钥匙和房间

DFS

class Solution {
public:
    vector<int> visit;
    vector<vector<int>> adj;
    int num=0;
    void dfs(int i)
    {
        visit[i]=1;
        num++;
        for(auto x:adj[i])
        {
            if(!visit[x]) dfs(x);
        }
    }
    bool canVisitAllRooms(vector<vector<int>>& rooms) {
        int n=rooms.size();
        visit.resize(n);
        adj.resize(n);
        for(int i=0;i<n;i++)
        {
            for(auto x:rooms[i]) adj[i].push_back(x);
        }
        dfs(0);
        return num==n;
    }
};

BFS

class Solution {
public:
    bool canVisitAllRooms(vector<vector<int>>& rooms) {
        int n=rooms.size();
        vector<int> visit;
        vector<vector<int>> adj;
        visit.resize(n);
        adj.resize(n);
        for(int i=0;i<n;i++)
        {
            for(auto x:rooms[i]) adj[i].push_back(x);
        }
        queue<int> q;
        q.push(0);
        visit[0]=1;
        int num=0;
        while(!q.empty())
        {
            int i=q.front();
            q.pop(); num++;
            for(auto x:adj[i])
            {
                if(!visit[x]) 
                {
                    q.push(x);
                    visit[x]=1;
                }
            }
        }
        return num==n;
    }
};