Find Second Largest Number From Array | Java Interview Questions and Answers

In this video, we showed you how to find the second highest number in Java.

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[pradeepkundekar]

Answer: Yes it will definitely work.
I have few approaches to solve this problem:
Approach 1:
Step 1: Add all the elements in a Set.
Step 2: Now add all elements from set into a new ArrayList and Sort.
Step 3 : Get size -2 th element
Time Complexity O(nlogn)
Space Complexity O(n)


Approach 2: (Using Heap or PriorityQueue)
Step 1: Add All elements into a set to remove duplicates
Step 2: Iterate through each elements of the set and add it into the Min Heap.
Step 3: Check if the size of Heap >2 then pop the top elements.
Step 4: Return Top element
Time Complexity: O(nlog2)
Space Complexity:O(n)
If there were no Duplicates then Space Complexity can Be constant.

[unknownplayer]

program will continue to work as expected. thank you for the video

[sathiskumarp]

It will work as expected, since we are checking the highest number logic!!!

[sandeshkulkarni]

I think first we have to remove duplicate elements from array and then we sort,
After that there no problem if we give any updated array

[bheemshankar_pk]

Good Logic Thanks, what if there are null values in array, then how to find 2nd largest??

[newanurag]

Just using the builtin functions.
where is the brain applied?

[stayvloging]

public class {
public static void main(String[] args) {

int arr[] = { 1, 4, 35, 34, 35, 35 };

int largest = arr[0];
int secondLargest = arr[0];

for (int i = 0; i < arr.length; i++) {
if (largest < arr[i]) {
secondLargest = largest;
largest = arr[i];
} else if (secondLargest < arr[i] && largest > arr[i]) {
secondLargest = arr[i];
}
}



}
}

[rmcf]

Will this work in an array of 100, 000 integers?

[princemohammed]

For bigger test cases it is not working

[trendinguniverse]

Bro pls make remove duplicate elements from array

[akhilraj]

I don't think last code is suitable for all testcases

[chaitanaywaskar]

at some cases of gfg, this code don't work .

[nitheeshreddy]

hi bro i have used this logic can u please check this..

int array[]=new int [] {1, 4, 5, 35, 35, 35, 34};

Arrays.sort(array); //1, 2, 4, 34, 35, 35;
int

for(int i=array.length-2;i>=0;i--) {
{



}

[wewgkic]

If I add second largest element two time
Then this logic will give error

[ChennaiCineCuts]

Better to make it as Hashset to remove duplicates

[yogeshganpule]

This will fail in case you have 2 duplicate elements as smallest . for ex int[] arr = {1, 2, 5, 7, 8, 9, -14, 56, 98, -3, -14, 2};

[shaikhkhizar]

This logic won't work, if we take the array elements as a input from user.

[jeckrazi]

Hi @CloudTech,

Stream.of(1, 4, 5, 35, 34, 35)
.sorted((n1, n2)-> Integer.compare(n2, n1))
.distinct()
.limit(2)
.skip(1)