/* Convert the following code using recursion,
and describe in plain English what the function
does using a comment. */

#include <stdio.h>

int foo(int A[], int x, int n);

int main() {
  int A[] = { 2, 3, -7, 10, -20, 5 };
  printf("foo(): \n");
  printf("%d\n", foo(A, 0, 1));
  printf("%d\n", foo(A, 1, 3));
  printf("%d\n", foo(A, 2, 5));
}

int foo(int A[], int x, int n) {
  int res = 0;
  while (x <= n) {
    if (A[x] % 2 == 0) {
      res++;
    }
    x++;
  }
  return res;
}