/* File: func1.c
   passing an (int -> int) function pointer in C
*/

#include <stdio.h>


int add3(int m) {
   return m + 3 ;
}


int add5(int m) {
   return m + 5 ;
}


void apply( int (*f) (int), int A[], int n) {
   for (int i=0 ; i < n ; i++) {
      A[i] = f( A[i] ) ;
   }
}

int main () {
   int B[10] = { 10, 11, 12, 13, 14, 15, 16, 17, 18, 19} ;

   printf("Before:\n") ;
   for (int i=0 ; i < 10 ; i++) {
      printf("   B[%d] = %d\n", i, B[i]) ;
   }

   apply (add3, B, 10) ;

   printf("\n\nAfter calling apply(add3, B, 10):\n") ;
   for (int i=0 ; i < 10 ; i++) {
      printf("  B[%d] = %d\n", i, B[i]) ;
   }

   apply (add5, B, 10) ;

   printf("\n\nAfter calling apply(add5, B, 10):\n") ;
   for (int i=0 ; i < 10 ; i++) {
      printf("  B[%d] = %d\n", i, B[i]) ;
   }

}