View Compilation Error

0_0_30243455_15536.cpp: In constructor 'node::node(int, int, int)':
0_0_30243455_15536.cpp:18:55: error: class 'node' does not have any field named 'flag'
     node(int t, int n, int f) : to(t), next(n), f(f), flag(false) {}
                                                       ^
0_0_30243455_15536.cpp: In function 'void solve()':
0_0_30243455_15536.cpp:124:12: error: 'pl' was not declared in this scope
         if(pl[i].f) {   ///如果有柱子
            ^