View Compilation Error

0_0_32291490_443.cpp: In function 'void dp(int)':
0_0_32291490_443.cpp:2:3: error: 'v' was not declared in this scope
   v[x]=1; 
   ^
0_0_32291490_443.cpp:3:22: error: 'head' was not declared in this scope
   for(register int i=head[x];i;i=nxt[i]){
                      ^
0_0_32291490_443.cpp:3:34: error: 'nxt' was not declared in this scope
   for(register int i=head[x];i;i=nxt[i]){
                                  ^
0_0_32291490_443.cpp:4:13: error: 'ver' was not declared in this scope
       int y=ver[i];
             ^
0_0_32291490_443.cpp:7:7: error: 'ans' was not declared in this scope
       ans=max(ans,d[x]+d[y]+edge[i]);
       ^
0_0_32291490_443.cpp:7:19: error: 'd' was not declared in this scope
       ans=max(ans,d[x]+d[y]+edge[i]);
                   ^
0_0_32291490_443.cpp:7:29: error: 'edge' was not declared in this scope
       ans=max(ans,d[x]+d[y]+edge[i]);
                             ^
0_0_32291490_443.cpp:7:36: error: 'max' was not declared in this scope
       ans=max(ans,d[x]+d[y]+edge[i]);
                                    ^