View Compilation Error

0_0_26754939_21149.cpp:7:9: error: 'maxn' was not declared in this scope
 int num[maxn];
         ^
0_0_26754939_21149.cpp:8:16: error: 'maxn' was not declared in this scope
 vector<int>vec[maxn];
                ^
0_0_26754939_21149.cpp: In function 'void dfs(int, int)':
0_0_26754939_21149.cpp:12:5: error: 'num' was not declared in this scope
     num[u]=1;
     ^
0_0_26754939_21149.cpp:13:19: error: 'vec' was not declared in this scope
     for(int i=0;i<vec[u].size();i++)
                   ^
0_0_26754939_21149.cpp: In function 'int main()':
0_0_26754939_21149.cpp:27:13: error: 'num' was not declared in this scope
         mst(num,0);
             ^
0_0_26754939_21149.cpp:3:26: note: in definition of macro 'mst'
 #define mst(a,b) memset((a),(b),sizeof(a))
                          ^
0_0_26754939_21149.cpp:31:13: error: 'vec' was not declared in this scope
             vec[i].clear();
             ^
0_0_26754939_21149.cpp:36:13: error: 'vec' was not declared in this scope
             vec[u].push_back(v);
             ^