#include<stdio.h>
main()
{
static int a[20];
int i=0;
a[i]=i++;
printf("%d %d %d",a[0],a[1],i);
}

output : 0 0 1

My question is while incrementing i at
a[i]=i++;

In output i value is 1 ,then why a[0] value is not incremented
wont the output be 1 0 1