View Compilation Error

0_0_34540269_12617.cpp: In function 'void bfs()':
0_0_34540269_12617.cpp:65:17: error: 'pre' was not declared in this scope
                 pre[j]=u;
                 ^
0_0_34540269_12617.cpp: In function 'int main()':
0_0_34540269_12617.cpp:142:33: error: 'pre' was not declared in this scope
         for(int i=0;i<=n+1;i++) pre[i]=0,h[i]=-1;
                                 ^