先离线处理出在[0,10^9)内中所有平方末尾数为987654321的数，然后显然应该写成下面那样。
CODE:
/*
AUTHOR: Su Jiao
DATE: 2010-9-11
DESCRIPTION:
$DESCRIPTION
*/
#include <stdio.h>
int main()
{
/*
for (long long int i=0;i<1000000000;i++)
if (i*i%1000000000==987654321) printf(“%d\n”,int(i));
output:
111111111
119357639
380642361
388888889
611111111
619357639
880642361
888888889
*/
int n;
scanf(“%d”,&n);
if (n<=8) printf(“%d\n”,0);
else if (n==9) printf(“%d\n”,8);
else
{
printf(“%d”,72);
for (int i=10;i<n;i++) printf(“%d”,0);
printf(“\n”);
}
}