View Compilation Error

0_0_27129023_30463.cpp:1:3: error: expected unqualified-id before 'if'
   if(u == ed) return ;
   ^
0_0_27129023_30463.cpp:2:3: error: expected unqualified-id before 'if'
   if (used[u]) continue;
   ^
0_0_27129023_30463.cpp:3:3: error: 'used' does not name a type
   used[u] = 1;
   ^
0_0_27129023_30463.cpp:4:6: error: expected constructor, destructor, or type conversion before '(' token
   erp(u) if (G.a[it].vis)
      ^