secondLargest.java

// Given an array of positive integers arr[], return the second largest element from the array. If the second largest element doesn't exist then return -1.

// Note: The second largest element should not be equal to the largest element.

// Examples:

// Input: arr[] = [12, 35, 1, 10, 34, 1]
// Output: 34
// Explanation: The largest element of the array is 35 and the second largest element is 34.
// Input: arr[] = [10, 5, 10]
// Output: 5
// Explanation: The largest element of the array is 10 and the second largest element is 5.
// Input: arr[] = [10, 10, 10]
// Output: -1
// Explanation: The largest element of the array is 10 and the second largest element does not exist.
// Constraints:
// 2 ≤ arr.size() ≤ 105
// 1 ≤ arr[i] ≤ 105

// Solution:

class Solution {
    public int getSecondLargest(int[] arr) {
        // Code Here
        int n = arr.length;
        int max = -1, secondMax = -1;
        
        for (int i = 0; i < n; i++) {
            if (arr[i] > max) {
                secondMax = max;
                max = arr[i];
            }
            else if (arr[i] < max && arr[i] > secondMax) {
                secondMax = arr[i];
            }
        }
        return secondMax;
    }
}