Linear Search
Searching O(n) O(1)Walks the array element by element until the target is found — works on any array, sorted or not.
23
7
41
15
3
34
9
28
Scanning 8 elements for 15.
InvariantEvery index before i has been checked and is not the target.
1/6
probes0i0
linear-search.c
int linearSearch(int arr[], int n, int target) {for (int i = 0; i < n; i++) {if (arr[i] == target)return i;}return -1;}
How Linear Search works
Walk the array front to back and compare each element with the target until you hit it or run out.
Best case
Target is the first element: O(1).
Worst case
Target is last or absent: O(n).
When to use it
Unsorted or tiny arrays, linked lists, or when you search only once so sorting wouldn't pay off.