/*
 * simple example of for loop and array, revised to show some things
 * about arrays versus pointers
 */
#include <stdio.h>

#define N 10

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

int main(void) {
    int nums[N];

    set_array(N, nums);
    print_array(N, nums);
    int index;
    printf("enter index\n");
    if (scanf("%d", &index) != 1) {
        printf("error\n");
        return 1;
    }
    nums[index] = -1;
    printf("%d\n", nums[index]);
    print_array(N, nums);

    return 0;
}

/*
 * print values in array indexing with pointer rather than index
 * (totally contrived!)
 */
void print_array(int sz, int a[]) {

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

/* 
 * observe that we can change the values in the array -- seems like it 
 * contradicts "pass by value" but no, since what's passed is pointer
 */
void set_array(int sz, int a[]) {
    for (int i = 0; i < sz; ++i) {
        a[i] = i+1;
    }
}