Searching CS Thinking Example 1
Follow the full solution, then compare it with the other examples linked below.
Example 1
mediumUse linear search to find the value 7 in the list [3, 9, 7, 1, 5]. How many comparisons are needed?
Solution
- 1 Step 1: Compare 3 with 7 — no match. Compare 9 with 7 — no match.
- 2 Step 2: Compare 7 with 7 — match found at index 2.
- 3 Step 3: 3 comparisons were needed.
Answer
Found at index 2 after 3 comparisons.
Linear search checks elements one by one from the start. It works on any list (sorted or unsorted) but can be slow for large lists — worst case is .
About Searching
The process of locating a specific item or value within a collection of data using a systematic strategy. The two fundamental approaches are linear search (check every element one by one) and binary search (repeatedly halve the search space in sorted data).
Learn more about Searching →More Searching Examples
Example 2 medium
Use binary search to find 23 in the sorted list [5, 10, 15, 20, 23, 30, 35]. Show each step.
Example 3 mediumCan binary search be used on the unsorted list [8, 2, 5, 1, 9]? Why or why not?
Example 4 hardA sorted list has 128 elements. In the worst case, about how many comparisons does binary search nee