Finding Occurance of Max Value in Array

Question

I am trying to find the Occurrences of a Maximum value in Integer Array.

e.g.

int[] ar = [3, 1, 2, 3];

Here, the Max 3 is repeated twice and so the expected output is 2.

This works, I am getting count as 2 as the max value 3 occurred twice in the array

var max = int.MinValue;
var occurrenceCount = 0;

foreach(var x in ar)
{
    if (x >= max) max = x;
}

foreach(var x in ar)
{
    if (x == max) occurrenceCount++;
}

Output: 2 //occurrenceCount

With Linq it's more simple,

var occurrenceCount = ar.Count(x => x == ar.Max())

Output: 2 //occurrenceCount

Now without Linq, Is there any simplified or efficient way to do this?

Answer 1

At least, you can merge the two first arrays. I would still use the Linq solution. It is clearer. If you really want to talk about performance read Which is faster? first.

So here is a O(n) solution:

int[] ar = {3, 1, 2, 3, 3, 4, 4};
int max = ar[0];
var occurrenceCount = 1;

for(var i = 1; i < ar.Length; i++)
{
    if (ar[i] > max) {
	max = ar[i];
	occurrenceCount = 1;
    }
    else if (ar[i] == max) {
        occurrenceCount++;
    }
}

WriteLine(max);
WriteLine(occurrenceCount);

Try it online!

• Note that you should handle the case where you array is empty.