Mars Exploration Hackerrank Solution - java

 Mars Exploration Hackerrank Solution - java

For Explanation watch video: 

Code::  

import java.io.*;

import java.math.*;

import java.security.*;

import java.text.*;

import java.util.*;

import java.util.concurrent.*;

import java.util.function.*;

import java.util.regex.*;

import java.util.stream.*;

import static java.util.stream.Collectors.joining;

import static java.util.stream.Collectors.toList;

class Result {

    /*

     * Complete the 'marsExploration' function below.

     *

     * The function is expected to return an INTEGER.

     * The function accepts STRING s as parameter.

     */

    public static int findDifferentLetters(String s){

        int count = 0;

        if(s.charAt(0)!='S'){

            count++;

        }

         if(s.charAt(1)!='O'){

            count++;

        }

         if(s.charAt(2)!='S'){

            count++;

        }

        return count;

    }

    public static int marsExploration(String s) {

        int ans = 0;

        for(int i=0;i<=s.length()-3;i=i+3){//SOS SOS SOS

            if(!s.substring(i,i+3).equals("SOS")){

                ans += findDifferentLetters(s.substring(i,i+3));

            }

        }

        return ans;//0

    }

}

public class Solution {

    public static void main(String[] args) throws IOException {

        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));

        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

        String s = bufferedReader.readLine();

        int result = Result.marsExploration(s);

        bufferedWriter.write(String.valueOf(result));

        bufferedWriter.newLine();

        bufferedReader.close();

        bufferedWriter.close();

    }

}