/in/foo.c: In function 'main':
/in/foo.c:11:3: warning: implicit declaration of function 'mult' [-Wimplicit-function-declaration]
   mult(re,i,&n);
   ^~~~
/in/foo.c:12:3: warning: implicit declaration of function 'cls' [-Wimplicit-function-declaration]
   cls(re,&n);
   ^~~
/in/foo.c:5:19: warning: unused variable 'x' [-Wunused-variable]
     int a,b,t,i,j,x;
                   ^
/in/foo.c:5:17: warning: unused variable 'j' [-Wunused-variable]
     int a,b,t,i,j,x;
                 ^
/in/foo.c:5:13: warning: unused variable 't' [-Wunused-variable]
     int a,b,t,i,j,x;
             ^
/in/foo.c:5:11: warning: unused variable 'b' [-Wunused-variable]
     int a,b,t,i,j,x;
           ^
/in/foo.c: At top level:
/in/foo.c:18:6: warning: conflicting types for 'mult'
 void mult(char * a,int b,int *c){
      ^~~~
/in/foo.c:11:3: note: previous implicit declaration of 'mult' was here
   mult(re,i,&n);
   ^~~~
/in/foo.c:33:6: warning: conflicting types for 'cls'
 void cls(char *a,int *b){
      ^~~
/in/foo.c:12:3: note: previous implicit declaration of 'cls' was here
   cls(re,&n);
   ^~~