Question

JAVAThe method longestStreak is intended to determine the longest substring of consecutive identical characters in the parameter str and print the result.For example, the call longestStreak("CCAAAAATTT!") should print the result "A 5" because the longest substring of consecutive identical characters is "AAAAA".
Complete the method below. Your implementation should conform to the example above.
public static void longestStreak(String str)

Answer 1

Answer:

public static void longestStreak(String str){

       int maxCharacterCount = 0;

       char longestSubString = str.charAt(0);

       

       for(int i=0; i<str.length(); i++){

           

           int currentMaxCharacterCount = 1;

           

           for(int j=i+1; j<str.length(); j++){

               if(str.charAt(i) != str.charAt(j)){

                   break;

               }

               else {

                   currentMaxCharacterCount++;

               }

           }  

           if (currentMaxCharacterCount > maxCharacterCount) {

                   maxCharacterCount = currentMaxCharacterCount;

                   longestSubString = str.charAt(i);

           }

       }

       System.out.println(longestSubString + " "+ maxCharacterCount);

   }



Explanation:

Let's start from the top of the code and go all the way down.

- Two variables created; maxCharacterCount to count the longest character in the string, and longestSubString to save the current longest substring. Initially they are set to 0 and the first character of given string respectively.

- We need to check all the substrings to find longest one. That is why a nested for loop (for loop inside a for loop) is created.

- The first loop starts from the first character of the given string and goes until the end of the given string.

- Inside the first loop, currentMaxCharacterCount is created to hold the current value of the maximum character in the given string.

- The second loop starts from the second character of the string, and checks if the character is same as the one that is being checked by the first loop.

- If they are not same, then the loop stops.

- If they are the same characters, currentMaxCharacterCount is incremented by 1. (That means we may find our new longest substring)

* Reminder: When the i is equal to 0, j is increasing from 1 to given string length. When i is equal to 1 j is increasing from 2 to given string length and so on. This process repeats for all i and j values to find out the longest substring.

- If currentMaxCharacterCount is greater than maxCharacterCount, that means we have a new longest substring, and maxCharacterCount should be equal to this new substring's count.

- Then, to be able to check for the next possible longest substring, it should continue from the next iteration of the i (longestSubString = str.charAt(i);)

- Finally, when the loops are done checking, longestSubString and maxCharacterCount need to be printed.