How to find second largest number in array without sorting Java

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In this post, we will see how to find the second largest number in an array.

Problem :

Given an unsorted array, you need to find the second largest element in the array in o(n) time complexity.
For example:

int[] arr1={7,5,6,1,4,2};
Second largest element in the array : 6

Solution:

You can sort the array and then return second last element in the array but it will be done in o(nlogn)  time,

Algorithm:

• Initialize highest and secondHighest with minimum possible value.
• Iterate over array.
• If current element is greater than highest
  • Assign secondHighest = highest
  • Assign highest = currentElement
• Else if current element is greater than secondHighest
  • Assign secondHighest =current element.

Create the main java class named FindSecondLargestMain.java

FindSecondLargestMain.java

Second largest element in the array : 6

That’s all about how to find second largest number in an array.

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