CODEWITHSUNDEEP
javasplit
Chatura Mohotti
Chatura Mohotti

Reputation: 83

Get the number of characters

I need to get the count of each repeated characters separately....I have tried..but it returns only the count of unique count of characters...

Input :

SSDDVVDSSS

output :

S - 5
D - 3
V - 2

here is my code

public class q2 {

public static void main(String[] args) {

   System.out.println(countUniqueCharacters("SSDDVVDSSS"));
}


public static int countUniqueCharacters(String input) {
boolean[] isItThere = new boolean[Character.MAX_VALUE];
for (int i = 0; i < input.length(); i++) {
    isItThere[input.charAt(i)] = true;
}

int count = 0;
for (int i = 0; i < isItThere.length; i++) {
    if (isItThere[i] == true){
        count++;
    }
}

return count;
}


}

Upvotes: 1

Views: 594

Answers (3)

SMA
SMA

Reputation: 37073

Following are the issues in your code:

  1. you are defining array with 65535 size which is unnecessary for 26 characters.
  2. You defined boolean array within which each element would store two values either true or false which is very much needed if you need to see if character exists in your String but doesn't suits your algorithm.
  3. You have shared counter variable which is going to give you length of String i.e. how many characters you have in your string and is not what you need.

There are multiple ways in which you could solve this problem:

  • Using int array with index from 0 - 26 that maintains count of character A-Z and finally you print the count:

        public static void main(String[] args) {
    int[] counts = countUniqueCharacters("SSDDVVDSSS");
    for (int i = 0; i < counts.length; i++) {
        if (counts[i] != 0) {
            System.out.println("char " + ((char) ('A' + i)) + " repeated " + counts[i] + " times");
        }
    }
}

    public static int[] countUniqueCharacters(String input) {
    int[] counts = new int[26];
    for (int i = 0; i < input.length(); i++) {
        counts[input.charAt(i) - 'A']++;
    }
    return counts;
}

  • Another way is to use map with character as key and int as value which would represent the count of that character repeatation.

Upvotes: 1

zohar
zohar

Reputation: 2378

Your last 'for' loop goes over the counter array and count how much entries with true value it contains. Therefore you get number of unique chars.

Try this:

public class q2 {

public static void main(String[] args) {

    countUniqueCharacters("SSDDVVDSSS");
}


public static void countUniqueCharacters(String input) {


    Map<Character,Integer>  map = new HashMap<Character, Integer>();

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

        if (map.get(input.charAt(i)) == null){
             map.put(input.charAt(i),1);
        }
        else{
            map.put(input.charAt(i),map.get(input.charAt(i))+1);
        }
    }

     System.out.print(map);
}

}

Upvotes: 0

Arun Kumar
Arun Kumar

Reputation: 2934

public static void main(String[] args) {
        String str = "SSDDVVDSSS";
        int counts[] = new int[(int) Character.MAX_VALUE];

        for (int i = 0; i < str.length(); i++) {
            char c = str.charAt(i);
            counts[(int) c]++;
        }

        for (int i = 0; i < counts.length; i++) {
            if (counts[i] > 0)
                System.out.print((char) i + "-" + counts[i] + "\n");
        }
    }

Upvotes: 0

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