Repeated String HackerRank Solution | Java Solution | Programming Blog

Repeated String Solution in Java

Lilah has a string s of lowercase English letters that she repeated infinitely many times. Given an integer n, find and print the number of letter a in the first n letters of Lilah's infinite string.

For example, if the string s = "abcac" and n = 10, the substring we consider it "abcacabcac" the first 10 character of her infinite string. There are 4 occurrences of a in the substring.

So let's see solution of that.

import java.util.Scanner;

public class RepeatedString {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        System.out.println("Enter Number");
        int number = sc.nextInt();

        System.out.println("Enter String");
        String str = sc.next();
       
        int lengthOfstr = str.length();
       
        long occurenceOfA = 0;

        // Get all occurence of 'a' in given string
        for(int i=0; i< lengthOfstr;i++) {
            if(str.charAt(i)=='a') {
                occurenceOfA++;
            }
        }

        // Get repeated string length
        long totalOccurence = occurenceOfA * ( number/lengthOfstr);
        long remainingStr = number % lengthOfstr;

        // Loop through remaining string and count occurence
        // of 'a' character
        for(int i=0; i<remainingStr; i++) {

            char ch = str.charAt(i);
            if(ch == 'a')
                totalOccurence++;
            }

        System.out.println(totalOccurence);   

    }   

}

Output :-
Enter Number
10
Enter String
aba
7

Enter Number
100000000
Enter String
a
100000000

See other solution of HackerRank's Problem

• https://uniquethrowdown.blogspot.com/2020/10/sales-by-match-hackerrank-java-solution.html 
• https://uniquethrowdown.blogspot.com/2020/10/counting-valleys-hackerrank-solution-in.html