View Compilation Error

0_0_29027123_17411.cpp: In function 'void add_edge(int, int, int)':
0_0_29027123_17411.cpp:12:27: error: 'to' was not declared in this scope
     edge[count_edge].to = to;           //下一个点为to
                           ^
0_0_29027123_17411.cpp:13:31: error: 'f1' was not declared in this scope
     edge[count_edge].weight = f1;            //容量
                               ^
0_0_29027123_17411.cpp:14:34: error: 'from' was not declared in this scope
     edge[count_edge].next = head[from]; //上次出现在最后一条出边
                                  ^