Linear Search with Time Complexity in DSA using C++

Program 1

// Program for Linear Search
#include<iostream>
#define clrscr() system("cls")
using namespace std;
class Search
{
    public:
      int linearSearch(int ar[],int n,int s);
      int pos;
};
  int Search::linearSearch(int ar[],int n,int s)
    {
            int i;
            for(i=0;i<n;i++)
            {
                
                if(ar[i]==s)
                {
                    pos=i;
                   return 1;
                }  
            }
            return 0;
    }
    int main()
    {
        int a[500],n,s;
        xyz:cout<<"\n Enter the limit\n";
        cin>>n;
        if(n<0 || n>500)
        {
            cout<<"\n Invalid limit enter again";
            goto xyz;
        }
        else
        {
            int i;
            cout<<"\n Enter element in array\n";
            for(i=0;i<n;i++)
            cin>>a[i];
            cout<<"\nEnter an element for search";
            cin>>s;
            Search S1;
            if(S1.linearSearch(a,n,s))
            {
              cout<<"\n Searching success";
              cout<<"\n Element found at position: "<<S1.pos+1;
            } 
              else
              cout<<"\n Searching not success";
            if(S1.pos==0)  
              cout<<"\nBest Case";
            else
            if(S1.pos>=0 && S1.pos<n)  
               cout<<"\nAverage Case";
             else
                 cout<<"\nWorst Case";
        }

        return 0;

    }