Question

C++ C++ C++ Write a program that will provide evidence as to which algorithm will search an array faster, Linear (sequential) search or Binary Search. Your program should test many different scenarios. Please help with right answer.

Answer 1

Hi,

If the data is sorted then binary search algorithm is the best, else linear search is the best

let us assume our data is sorted then :

The worst-case and average-case time complexity for binary search is O(log n).

The worst-case and average-case time complexity is O(n).

As we know that  O(log n) is always lesser than O(n) [ O(log n) < O(n) ]
The following example shows the binary search is better than linear search

/* C++ Program - Binary Search */
        
#include<iostream.h>
#include<conio.h>
void main()
{
        clrscr();
        int n, i, arr[50], search, first, last, middle;
        cout<<"Enter total number of elements :";
        cin>>n;
        cout<<"Enter "<<n<<" number :";
        for (i=0; i<n; i++)
        {
                cin>>arr[i];
        }
        cout<<"Enter a number to find :";
        cin>>search;
        first = 0;
        last = n-1;
        middle = (first+last)/2;
        while (first <= last)
        {
                if(arr[middle] < search)
                {
                        first = middle + 1;

                }
                else if(arr[middle] == search)
                {
                        cout<<search<<" found at location "<<middle+1<<"\n";
                        break;
                }
                else
                {
                         last = middle - 1;
                }
                middle = (first + last)/2;
        }
        if(first > last)
        {
                cout<<"Not found! "<<search<<" is not present in the list.";
        }
        getch();
}