View Compilation Error

0_0_23715889_17881.cpp:10:5: error: 'M' was not declared in this scope
 } e[M+2];
     ^
0_0_23715889_17881.cpp: In function 'void addedge(int, int)':
0_0_23715889_17881.cpp:18:2: error: 'e' was not declared in this scope
  e[++m].v = v;
  ^
0_0_23715889_17881.cpp: In function 'void Tarjan(int)':
0_0_23715889_17881.cpp:25:24: error: 'e' was not declared in this scope
  for(int i=fe[u]; i; i=e[i].nxt)
                        ^
0_0_23715889_17881.cpp: In function 'int main()':
0_0_23715889_17881.cpp:47:165: error: 'e' was not declared in this scope
   sn = tp = id = 0; memset(dfn,0,sizeof(dfn)); memset(low,0,sizeof(low)); memset(sta,0,sizeof(sta)); memset(fe,0,sizeof(fe)); memset(ins,false,sizeof(ins)); memset(e,0,sizeof(e));
                                                                                                                                                                     ^