Count 1's between numbers

Count how many 1's in range of numbers
ex: 1 to 20 equals to twelve 1's

1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20
^                         ^   ^ ^ ^   ^   ^   ^   ^   ^   ^   ^

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

import java.util.*; public class CountOne{ public static void main(String[] args){ int n=20; long i = 0, j = 1; long count = 0; for (i = 1; i <= n; i ++) { j = i; while (j != 0) { if (j % 10 == 1) count ++; j /= 10; } } System.out.print(count); } }