//Time Complexity : O(d), where 'd' is the digits of number import java.io.*; import java.util.*; public class CountDigits { static int countDigits(int num) { int count = 0; while(num > 0) { num = num / 10; count++; } return count; } public static void main (String[] args) { int number = 789; System.out.println(countDigits(number)); } }