/*
 * Program to demonstrate using array and "for".
 */
#include <stdio.h>

void print_array(int sz, int a[]);

#define N 6

/* main program */
int main(void) {

    /* declare/create array */
    int num[N];

    /* initialize array */
    for (int i = 0; i < N; ++i) {
        num[i] = i + 1;
    }
    print_array(N, num);

    printf("enter index\n");
    int index;
    if (scanf("%d", &index) != 1) { printf("error\n"); return 1; }
    /* should check for index < 0 or >= N here!! */
    num[index] = -1;
    print_array(N, num);
    return 0;


}

void print_array(int sz, int a[]) {
    for (int i = 0; i < sz; ++i) {
        printf("elem %d is %d\n", i, a[i]);
    }
}