/in/foo.c: In function 'main':
/in/foo.c:6:2: warning: 'gets' is deprecated [-Wdeprecated-declarations]
gets(s);
^~~~
In file included from /in/foo.c:1:0:
/usr/include/stdio.h:640:14: note: declared here
extern char *gets (char *__s) __wur __attribute_deprecated__;
^~~~
/in/foo.c:7:2: error: unknown type name 'bool'
bool flag=false;
^~~~
/in/foo.c:7:12: error: 'false' undeclared (first use in this function)
bool flag=false;
^~~~~
/in/foo.c:7:12: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:13:13: error: 'true' undeclared (first use in this function)
if(flag==true) ei=i-1;
^~~~