How do you find the second largest element in an unsorted array?

Difficulty: 2/10

array traversal, single-pass algorithm, space optimization

Second Largest Element

The optimal single-pass solution maintains the largest and second-largest distinct values while scanning the array once. This avoids sorting, which would require O(n log n) time.

javascript

1
Time complexity: O(n).
2
Auxiliary space: O(1).
3
The comparison x != first ensures the second value is distinct.
4
Edge cases such as fewer than two distinct values should be handled explicitly.

Scenario Questions

0-2 years experience

Follow-up Questions