View Compilation Error

0_0_21538779_21586.cpp: In function 'void EKMP(char*, int, char*, int, int*, int*)':
0_0_21538779_21586.cpp:3:24: error: 'pre_EKMP' was not declared in this scope
     pre_EKMP(x, m, next);
                        ^
0_0_21538779_21586.cpp:14:28: error: 'max' was not declared in this scope
             j =max(0, p-i+1);
                            ^