CODEWITHSUNDEEP
arraysalgorithmmaxarray-algorithms
42times
42times

Reputation: 11

How to find second max element in an array in one iteration?

I need the second maximum element in an unsorted array in one iteration. eg: the array is 3 9 8 2 0 -4 87 45 3 2 1 0 The answer should be 45 , its very simple to find max element in one iteration , but how to find the second max in the same iteration , or constant time after the fort iteration of the array.

Upvotes: 1

Views: 2939

Answers (3)

Navin Prasad
Navin Prasad

Reputation: 1

function MathLib()
{
    this.getSecondMax=function(args)
    {
        var max = 0;
        var secondMax = 0;
        for(var i=0;i<arguments.length;i++)
        {
            if(arguments[i]>max)
            {
                secondMax = max;
                max = arguments[i];
            }
            else
            {
                if(secondMax<arguments[i])
                {
                    secondMax = arguments[i];
                }
            }
        }
        return secondMax;
    }
}

Upvotes: 0

Amadan
Amadan

Reputation: 198304

for each element:
  if element is bigger than max, max shifts to second-max, element becomes max
  else if element is bigger than second-max, element becomes second-max

Upvotes: 2

psyclaudeZ
psyclaudeZ

Reputation: 76

int sz = arr.size();
assert(sz >= 2);
int maxElem = arr[0];
int secElem = arr[1];
if (maxElem < secElem) swap(maxElem, secElem);

for (int i = 2; i < sz; ++i) {
    if (arr[i] > maxElem) {
        secElem = maxElem;
        maxElem = arr[i];
    } else if (arr[i] == maxElem) {
        secElem = maxElem;
    } else if (arr[i] < maxElem && arr[i] > secElem)) {
        secElem = arr[i];
    }
}

Upvotes: 2

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