Western Governors University (WGU) ICSC2100 C949 Data Structures and Algorithms I Practice Exam

In a hash table, collisions occur when multiple keys hash to the same index in the underlying array. When there is a high number of collisions, the performance of the hash table is adversely affected. Specifically, the time complexity for accessing elements becomes increased because resolving collisions typically involves additional operations such as chaining (linking collided entries in a list) or probing (searching for another open slot in the array).

As the load factor (the ratio of the number of stored entries to the number of slots in the hash table) increases due to numerous collisions, it can lead to longer search times, particularly for operations like insertion, deletion, and retrieval. Ideally, these operations should average to O(1) time complexity, but with many collisions, they can degrade to O(n) in the worst case, where n is the number of entries, primarily because finding the right entry might require traversing a linked list or checking multiple slots.

While other factors may influence the operational efficiency of hash tables, such as memory usage or implementation complexity, the core issue directly stemming from a high number of collisions is indeed the increased time complexity involved in accessing elements, making it the correct answer.