print and count the maximun values in 2d array java

Question

I have 2d array java, I need to look at it and check on the max value, then print it with the count of how many it is in the array

I was trying to do like this but it doesn't work

        int[][] rand = new int[][]{
                {1, 80, 3, 4, 5},
                {13, 199, 80, 8},
                {12, 22, 80, 190}
        };

        int max = rand[0][0];
        int count = 0;
        for (int i = 0; i < rand.length; i++){
            for (int ii = 0; ii < rand[i].length; ii++) {
                if (rand[i][ii] > max) {
                    max = rand[i][ii];
                    count++;
                }

            }
        }
        System.out.println(max + " " + count);

You are on the right path but you need to reset the count every time you find a value that is larger. This means you also need an if statement that says if the value is equal to the max then increase count — David Brossard
– David Brossard, Commented Dec 27, 2020 at 7:19
So in your code where it says count++ do count=1, and then add an else if statement to increase count when the value is equal to the max — David Brossard
– David Brossard, Commented Dec 27, 2020 at 7:20
In addition, you may want to handle empty arrays. The statement rand[0][0] will raise an OutOfBoundsException on an empty array. — pxcv7r
– pxcv7r, Commented Dec 27, 2020 at 7:26

Eran · Accepted Answer · 2020-12-27 08:24:12Z

2

You are not handling count correctly:

int max = rand[0][0];
int count = 0
for (int i = 0; i < rand.length; i++){
    for (int ii = 0; ii < rand[i].length; ii++) {
        if (rand[i][ii] > max) {
            max = rand[i][ii];
            count = 1; // a new maximum's first occurrence
        } else if (rand[i][ii] == max) {
            count++; // another occurrence of the current maximum
        }
    }
}
System.out.println(max + " " + count);

When you find a new maximum, you should reset count to 1.
You should check if the current element is equal to the current maximum, and increment count if that's the case.

Output:

199 1

EDIT:

Fixed the case where the first element is the maximum. It turns out count should be initialized to 0 after all, since the loops re-visit the first element, so we don't want to count it twice if it's the maximum.

edited Dec 27, 2020 at 8:24

answered Dec 27, 2020 at 7:19

Eran

395k57 gold badges726 silver badges793 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

A.Alexander Over a year ago

It is incorrect sollution. Try it for int[][] rand = new int[][]{ {200, 80, 199, 199, 5}, {13, 199, 80, 8}, {12, 22, 80, 200} };

Eran Over a year ago

@A.Alexander Oh, you are correct. count should be initialized to 0 after all.

Arvind Kumar Avinash Over a year ago

@Eran - We posted our answers almost at the same time but when I saw your answer, I didn't even realise that you had done that mistake and in the honour of a great as you, I deleted my answer which didn't have this mistake 😊.

A.Alexander · Accepted Answer · 2020-12-27 08:18:34Z

0

You can use streams:

    int max = Arrays.stream(rand)
            .mapToInt(row -> Arrays.stream(row).max().getAsInt())
            .max().getAsInt();

    int count = Arrays.stream(rand)
            .mapToInt(row -> (int) Arrays.stream(row).filter(i-> i==max).count())
            .reduce(Integer::sum).getAsInt();

answered Dec 27, 2020 at 8:18

A.Alexander

5983 silver badges14 bronze badges

Collectives™ on Stack Overflow

print and count the maximun values in 2d array java

2 Answers 2

3 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related