>>853の続き…
static void sieve( char *array, int max ) {
int i;
for ( i = 3; i < max/3; i += 2 ) {
if ( array[i/2-1] ) {
int j;

for ( j = i*2; j <= max; j += i ) {
if ( j&1 )
array[j/2-1] = 0;
}

if ( i != reverse_int(i) )
array[i/2-1] = 0;
}
}
for ( ; i <= max; i += 2 )
if ( array [i/2-1] && i != reverse_int(i) )
array[i/2-1] = 0;
}