页面历史记录

vector<int> visited;

void bfs(vector<vector<int>> &graph, int start) {
    queue<int> q;
    q.push(start);
    visited[start] = 1;
    
    while(!q.empty()) {
        int size = q.size();
        while(size-- > 0) {
            int cur = q.front(); q.pop();
            visited[cur] = 1;
            for(auto nxt : graph[n]) {
                if(!visited[nxt]) {
                    q.push(nxt);
                    visited[nxt] = 1;
                }
            }
        }
    }
}