Find Numbers with Even Number of Digits in Java | Programming Tutorial

Java Solution for Find Numbers with Even Number of Digits

Given an array nums of integers, return how many of them contain an even number of digits. 

Example 1 :-

Input: nums = [12,345,2,6,7896]
Output: 2
Explanation: 
12 contains 2 digits (even number of digits). 
345 contains 3 digits (odd number of digits). 
2 contains 1 digit (odd number of digits). 
6 contains 1 digit (odd number of digits). 
7896 contains 4 digits (even number of digits). 
Therefore only 12 and 7896 contain an even number of digits.

Example 2 :-

Input: nums = [555,901,482,1771]
Output: 1 
Explanation: 
Only 1771 contains an even number of digits.

So lets see solution in Java :-

Solution 1 :-

import java.util.Scanner;

public class FindNumberswithEvenNumberofDigits {

    public static void main(String[] args) {
        
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter Array Size");
        int arraySize = sc.nextInt();
        int[] array = new int[arraySize];
        
        System.out.println("Enter Array Values");
        for (int i = 0; i < arraySize; i++) {
            array[i] = sc.nextInt();
        }

        int totalEven = 0 ;
        for (int number : array) {
            String s = String.valueOf(number);
            if (s.length() % 2 == 0) {
                totalEven++;
            }
        }
        System.out.println(totalEven);
    }

}

Explanation :-

1. Get size of array using scanner.
2. Declare array and assign its value from user.
3. Loop through array values and convert into string.
4. Check if number is Even or not, If number is even then increment totalEven variable by 1.
5. Print totalEven value.

Solution 2 :-

import java.util.Scanner;

public class FindNumberswithEvenNumberofDigits {

    public static void main(String[] args) {
        
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter Array Size");
        int arraySize = sc.nextInt();
        int[] array = new int[arraySize];
        
        System.out.println("Enter Array Values");
        for (int i = 0; i < arraySize; i++) {
            array[i] = sc.nextInt();
        }

        int totalEven = 0;
        int count = 0;
         
        for (int i = 0; i < arraySize; i++) {
             int number = array[i];
            
             while(number > 0) {
                number = number / 10;
                count++;
            }
            
            if (count % 2 == 0) {
                totalEven++;
            }
            count = 0;
        }
        
     System.out.println(totalEven);
    }

}

Explanation :-

1. Get Array Size from user.
2. Insert values in array using for loop.
3. Loop through array values.
4. Divide the number using 10 until number become 0. And increment count by one. If number is Even then count will store even number otherwise Odd.
5. Last, check if (number % 2) become is 0 then it is Even otherwise Odd. and increment totalEven variable one if number is Even.

Happy Coding.

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