View Compilation Error

0_0_27949258_4343.cpp: In function 'int main()':
0_0_27949258_4343.cpp:34:37: error: 'oper' was not declared in this scope
     for(int i=0;i<n;i++)s[i] = oper();
                                     ^
0_0_27949258_4343.cpp:36:28: error: 'A' was not declared in this scope
     for(int now,i=m-1,last=A[id[m]];i>=0;i--,last=now){
                            ^