Home » Kotlin » Kotlin Programs » Kotlin Basic Programs

Kotlin program to print all palindromes in a given range

Kotlin | Print all palindromes in a given range: Here, we are going to learn how to check and print all palindrome numbers in a given range in Kotlin programming language? Submitted by IncludeHelp, on April 24, 2020

Kotlin - Print all palindromes in a given range

A palindrome number is a number that remains the same when its digits are reversed. Example: 16461.

Problem statement

Given a range from start to end, we have to check and print all palindromes numbers between start and end (includes start and end).

Example:

Input:
start = 1
end = 100

Output:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 
22, 33, 44, 55, 66, 77, 88, 99]

Program to print all palindromes in a given range in Kotlin

/**
 * Kotlin Program to check find out Palindrome number 
 * between given Range(include START and END)
*/

package com.includehelp.basic

import java.util.*


//Function to check Palindrome Number
fun findPalindrome(number: Long): Boolean {
    var isPalindromeNumber = false
    var sum : Long= 0
    var tempNum = number

    while (tempNum > 0) {
        val r = tempNum % 10
        sum = sum * 10 + r
        tempNum /= 10
    }
    if (sum == number) {
        isPalindromeNumber = true
    }
    return isPalindromeNumber
}

//Main Function, Entry Point of Program
fun main(arg: Array<String>) {
    //Input Stream
    val sc = Scanner(System.`in`)

    //Input Start of Range
    print("Enter Start of Range  : ")
    val start: Long = sc.nextLong()

    //Input End of Range
    print("Enter End of Range  : ")
    val end: Long = sc.nextLong()

    //Declare Mutable List to hold Palindromes
    val list: MutableList<Long> = ArrayList()

    //iterate through loop start to end to find Palindrome in Range
    for (i in start..end) {
        if (findPalindrome(i)) {
            list.add(i)
        }
    }

    println("Palindrome Numbers from $start to $end  : $list")
}

Output

RUN 1:
Enter Start of Range  : 1
Enter End of Range  : 100
Palindrome Numbers from 1 to 100  : [1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 
22, 33, 44, 55, 66, 77, 88, 99]
---
RUN 2:
Enter Start of Range  : 999
Enter End of Range  : 9999
Palindrome Numbers from 999 to 9999  : [999, 1001, 1111, 1221, 1331, 1441, 1551, 
1661, 1771, 1881, 1991, 2002, 2112, 2222, 2332, 2442, 2552, 2662, 2772, 2882, 
2992, 3003, 3113, 3223, 3333, 3443, 3553, 3663, 3773, 3883, 3993, 4004, 4114, 
4224, 4334, 4444, 4554, 4664, 4774, 4884, 4994, 5005, 5115, 5225, 5335, 5445, 
5555, 5665, 5775, 5885, 5995, 6006, 6116, 6226, 6336, 6446, 6556, 6666, 6776, 
6886, 6996, 7007, 7117, 7227, 7337, 7447, 7557, 7667, 7777, 7887, 7997, 8008, 
8118, 8228, 8338, 8448, 8558, 8668, 8778, 8888, 8998, 9009, 9119, 9229, 9339, 
9449, 9559, 9669, 9779, 9889, 9999]