1 #include <stdio.h> 2 3 extern int a(int); 4 extern int b(int); 5 extern int c(int); main(int argc,char const * argv[])6 int main (int argc, char const *argv[]) 7 { 8 printf ("a(1) returns %d\n", a(1)); 9 printf ("b(2) returns %d\n", b(2)); 10 printf ("c(2) returns %d\n", c(2)); 11 } 12