simplestack.c: At top level:
simplestack.c:915:7: error: conflicting types for ‘itoa’
char* itoa(int num, char* str, int base)
^~~~
simplestack.c:36:5: note: previous declaration of ‘itoa’ was here
int itoa(int,char*,int);
^~~~
simplestack.c: In function ‘itoa’:
simplestack.c:918:5: error: unknown type name ‘bool’; did you mean ‘_Bool’?
bool isNegative = false;
^~~~
_Bool
simplestack.c:918:23: error: ‘false’ undeclared (first use in this function); did you mean ‘base’?