A marine biology database stores the ocean depth readings (to the nearest meter) of 25,000 sonar pings in an unsorted array. Currently, a research assistant uses a linear search to locate a specific depth reading.
The assistant wants to drastically optimize the retrieval time. State one type of preprocessing that can be applied to the array of depth readings, and explain how the search process could be modified to locate the target depth reading more efficiently using the preprocessed data.