Linear Search Algorithm in DSA Typescript - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main idea behind the Linear Search Algorithm?

Linear Search checks each item in a list one by one until it finds the target or reaches the end.

beginner

What is the time complexity of Linear Search in the worst case?

The worst-case time complexity is O(n), where n is the number of items in the list.

intermediate

In which scenario is Linear Search preferred over other search algorithms?

When the list is small or unsorted, Linear Search is simple and effective without extra setup.

beginner

What does Linear Search return if the target is not found in the list?

It returns -1 or a special value indicating the target is not present.

beginner

Show a simple TypeScript code snippet for Linear Search.

function linearSearch(arr: number[], target: number): number {
  for (let i = 0; i < arr.length; i++) {
    if (arr[i] === target) {
      return i;
    }
  }
  return -1;
}

What does Linear Search do when it finds the target element?

A Sorts the list

B Stops and returns the index of the target

C Continues searching the entire list

D Deletes the target element

Linear Search stops immediately and returns the index when it finds the target.

What is the best case time complexity of Linear Search?

A O(n log n)

B O(n)

C O(log n)

D O(1)

Best case is when the target is the first element, so it takes constant time O(1).

Which of these lists is Linear Search most suitable for?

A A large sorted list

B A hash table

C A small unsorted list

D A balanced binary search tree

Linear Search works well on small or unsorted lists where other methods add overhead.

If the target is not in the list, what does Linear Search return?

A -1

B 0

C The last index

D The length of the list

Linear Search returns -1 to indicate the target was not found.

How does Linear Search check elements in the list?

A One by one from start to end

B Randomly

C From the middle to the ends

D Using binary splitting

Linear Search checks each element one by one from the start to the end.

Explain how Linear Search works step-by-step on a list of numbers.

Think about looking for a name in a phone book by checking every entry.

Describe when you would choose Linear Search over other search methods.

Consider situations where sorting or complex structures are not worth the effort.