If each component is equally likely to be searched, then linear search has an average case of n+1/2 comparisons, but the average case can be affected if the search probabilities for each component vary. In computer science, a linear search or sequential search is a method for finding an component within a list.

A linear search sequentially checks each component of the list until it finds an component that matches the target value. If the algorithm reaches the end of the list, the search terminates unsuccessfully.

```
#include <iostream>
using namespace std;
int LinearSearch(int *array, int size, int key)
{
for (int i = 0; i < size; ++i)
{
if (array[i] == key)
{
return i;
}
}
return -1;
}
int main()
{
int size;
cout << "\nEnter the size of the Array : ";
cin >> size;
int array[size];
int key;
//Input array
cout << "\nEnter the Array of " << size << " numbers : ";
for (int i = 0; i < size; i++)
{
cin >> array[i];
}
cout << "\nEnter the number to be searched : ";
cin >> key;
int index = LinearSearch(array, size, key);
if (index != -1)
{
cout << "\nNumber found at index : " << index;
}
else
{
cout << "\nNot found";
}
return 0;
}
```