/in/foo.cc: In function 'void findmax(int (*)[26], int, int)':
/in/foo.cc:55:22: warning: variable 'imax' set but not used [-Wunused-but-set-variable]
  int i,j,max=a[0][0],imax=0,jmax=0,b[N],nb=0;
                      ^~~~
/in/foo.cc:55:29: warning: variable 'jmax' set but not used [-Wunused-but-set-variable]
  int i,j,max=a[0][0],imax=0,jmax=0,b[N],nb=0;
                             ^~~~
/in/foo.cc:55:36: warning: unused variable 'b' [-Wunused-variable]
  int i,j,max=a[0][0],imax=0,jmax=0,b[N],nb=0;
                                    ^
/in/foo.cc:55:41: warning: unused variable 'nb' [-Wunused-variable]
  int i,j,max=a[0][0],imax=0,jmax=0,b[N],nb=0;
                                         ^~
/in/foo.cc: In function 'void cishu(char*)':
/in/foo.cc:83:32: warning: unused variable 'j' [-Wunused-variable]
  int a[26][26]={0},m=26,n=26,i,j,x,y,nn;
                                ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:114:2: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
  gets(s);
  ^~~~
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /usr/include/c++/6/ext/string_conversions.h:43,
                 from /usr/include/c++/6/bits/basic_string.h:5417,
                 from /usr/include/c++/6/string:52,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:114:8: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
  gets(s);
        ^
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /usr/include/c++/6/ext/string_conversions.h:43,
                 from /usr/include/c++/6/bits/basic_string.h:5417,
                 from /usr/include/c++/6/string:52,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/tmp/ccdF7YC4.o: In function `main':
foo.cc:(.text.startup+0xf): warning: the `gets' function is dangerous and should not be used.