Heap data structure enables efficient k-th largest element search

A developer encountered a problem to find the k-th largest element in an unsorted array during an interview. Sorting the entire array is inefficient for large datasets, requiring O(n log n) time. Using a min-heap of size k allows the algorithm to run in O(n log k) time, which is significantly faster when k is much smaller than n. The heap maintains the k largest elements seen while scanning the array once. This approach avoids examining every possible ordering while guaranteeing the correct result.