CODEWITHSUNDEEP
javaarraysaverage
Conor606
Conor606

Reputation: 107

Find the average of String Array

I have a String array for the passenger's nationality; 

String[] strNationality = new String[];

Users can input any nationality they like. However I have to find the average nationality. So, for example, if there were five people on bus of nationalities; German, German, German, French, Spanish. I can see German is clearly the average looking at it, but what would be the best way to create a method calculating the average?

Upvotes: 0

Views: 1079

Answers (3)

Pavan Dittakavi
Pavan Dittakavi

Reputation: 3181

I am assuming that your intention by average means most repeated country name. You can use a HashMap datastructure.

HashMap< String, Integer >: where String is the country name and Integer is going to be the count.

Once you are done with all the input, you simply need to iterate through the HashMap to find the largest value part and print the corresponding key part.

http://docs.oracle.com/javase/7/docs/api/java/util/Map.html

In your case it would look like:

KEY -> VALUE Germany -> 3 French -> 1 Spanish -> 1

Iterating through VALUE part of the Map would help you identify that 3 is the largest one and its key Germany is the one that you should be printing.

Algorithm would look like this:

  1. Read each entry from country array.
  2. If the current country is not in HashMap, then add it to the Map with KEY as country name and VALUE as 1.
  3. If the current country is present in HashMap, then update the existing entry with VALUE as 2.
  4. Repeat the above steps until the array is completely read.
  5. Iterate through the Map to find the highest VALUE.
  6. Get the corresponding KEY of the highest VALUE and print it.

Upvotes: 0

Ahmad Hammoud
Ahmad Hammoud

Reputation: 701

String[] strNationality = new String[]; //this array must be filled first.


string _MajorNationality = "";
int _RepeatedTimes = 0;
for(int i = 0; i < strNationality.length; i++){
    int currentRepeat = 0;
    for(int j = i; j < strNationality.length; j++){
        if(strNationality[i].equals(strNationality[j])){
            currentRepeat++;
        }
    }
    if(_RepeatedTimes < currentRepeat){
        _MajorNationality = strNationality[i];
        _RepeatedTimes = currentRepeat;
    }
}

//_MajorNationality would be the most repeated nationality.
//_RepeatedTimes would be how many times it repeated.

Upvotes: 0

sparkhee93
sparkhee93

Reputation: 1375

If there is an unknown number of nationalities, I would use Map to store the nationality as the key and the count as the value. If the next nationality exists, increment the value of that nationality within the Map object. If not, then create and new one and add it onto the Map object.

Map<String, Integer> nationalityCount = new Map<String, Integer>();
for(int i = 0 ; i < strNationality.length(); i++) {
    String nationality = strNationality[i];
    if(nationalityCount.containsKey(nationality) {
        int newCount = nationalityCount.get(nationality) + 1; 
        nationalityCount.put(nationality, newCount);
    }
    else {
        nationalityCount.put(nationality, 1);
    }
}

Upvotes: 4

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