Solution Repeated String Hacker Rank

Challenge:

Lilah has a string, , of lowercase English letters that she repeated infinitely many times.

Given an integer, , find and print the number of letter a's in the first  letters of Lilah's infinite string.

For example, if the string  and , the substring we consider is , the first  characters of her infinite string. There are  occurrences of a in the substring.

Function Description

Complete the repeatedString function in the editor below. It should return an integer representing the number of occurrences of a in the prefix of length  in the infinitely repeating string.

repeatedString has the following parameter(s):

• s: a string to repeat
• n: the number of characters to consider

Input Format

The first line contains a single string, .
The second line contains an integer, .

Constraints

• For  of the test cases, .

Output Format

Print a single integer denoting the number of letter a's in the first  letters of the infinite string created by repeating  infinitely many times.

Sample Input 0

aba
10

Sample Output 0

7

Explanation 0
The first  letters of the infinite string are abaabaabaa. Because there are  a's, we print  on a new line.

Sample Input 1

a
1000000000000

Sample Output 1

1000000000000

Explanation 1
Because all of the first  letters of the infinite string are a, we print  on a new line.

Approach:

1. Used a method "repeatedCharInString(String,long)" for knowing the count of  a char in the String.

Note: It is better to use basic for loop and charAt() method to know the count. Because using foreach and substring might cause runtime exceptions. Here we are dealing with long type.

2. Multiplied the character count with quotient and added with character count in the reminder string.

Solution:

static long repeatedString(String s, long n) {

        long stringLength = s.length();

        long quotient = n/stringLength;

        long reminder = n % stringLength;

        long count = 0;

        /*String reminderString = "";

        

        if(reminder != 0){

            reminderString = s.substring(0,reminder);

        }*/

        //String reminderString = s.substring(0,reminder);

        count = (quotient*repeatedCharInString(s, stringLength)) + (repeatedCharInString(s, reminder));

        

        return count;

    }

    static long repeatedCharInString(String s, long length){

        int count = 0;

        /*char[] chars = s.toCharArray();

        for(char ch : chars){

            if(ch == 'a')count++;

        }*/

        for(int i=0; i<length; i++){

            if(s.charAt(i) == 'a') count++;

        }

        return count;

    }