Menu Driven C++ program to implement Linear search and Binary search

/*-------------------------------------------------------------------------------------------------------------

File Name:      17 linearandbinary.cpp

Author:           sujith

Reg No:           141740

Program:        Write Menu Driven C++ program to implement the following

                                                              i.      Linear search

                                                            ii.      Binary search

Date:               23-04-2015

--------------------------------------------------------------------------------------------------------------*/

#include<iostream>

#include<stdio.h>

using namespace std;

int linearsearch(int a[20],int key,int n);

int binarysearch(int a[20],int key,int n);

int main()

{

        int a[20],k,n,ch,ans,i;

        cout<<"Enter the total number of elements\n";

        cin>>n;

        while(1){

                cout<<"\nMenu\n";

                cout<<"1.linear search\n";

                cout<<"2.binary search\n";

                cout<<"3.exit\n";

                cout<<"Enter your choice\n";

                cin>>ch;

                switch(ch){

                        case 1:

                                cout<<"Enter the elements\n";

                                for(i=0;i<n;i++){

                                        cin>>a[i];

                                }

                                cout<<"Enter the key elememts\n";

                                cin>>k;

                                ans=linearsearch(a,k,n);

                                if(ans!=-1)

                                        cout<<"element\t"<<k<<"\tis found\n";

                                else

                                        cout<<"Element\t"<<k<<"\tis not found\n";

                                break;

                        case 2:

                                cout<<"Enter the elements\n";

                                for(i=0;i<n;i++){

                                        cin>>a[i];

                                }

                                cout<<"Enter the key elememts\n";

                                cin>>k;

                                ans=binarysearch(a,k,n);

                                if(ans!=-1)

                                        cout<<"element\t"<<k<<"\tis found\n";

                                else

                                        cout<<"Element\t"<<k<<"\tnot found\n";

                                break;

                        case 3:

                                exit(0);

                        default:

                                cout<<"Invalid entry\n";

                }

        }

}

int linearsearch(int a[20],int key,int n)

{

        int i;

        for(i=0;i<n;i++){

                if(key==a[i])

                        return i;

        }

        return -1;

}

int binarysearch(int a[20],int key,int n)

{

        int high,low,mid;

        low=0;

        high=n-1;

        while(low<=high){

                mid=(low+high)/2;

                if(a[mid]==key)

                        return mid;

                else if(a[mid]<key)

                        low=mid+1;

                else

                        high=mid-1;

        }

        return -1;

}

OUTPUT:

[141740@localhost ~]$ g++ linearandbinary.cpp

[141740@localhost ~]$ ./a.out

Enter the total number of elements

5

Menu

1.linear search

2.binary search

Enter your choice

1

Enter the elements

1          5          6          7          4

Enter the key elememts

7

element 7   is found

Menu

1.linear search

2.binary search

3.exit

Enter your choice

1

Enter the elements

55        66        77        88        99

Enter the key elememts

100

Element 100  is not found

Menu

1.linear search

2.binary search

3.exit

Enter your choice

2

Enter the elements

15        55        66        44        22

Enter the key elememts

55

element 55      is found

Menu

1.linear search

2.binary search

3.exit

Enter your choice

2

Enter the elements

55        66        45        56        23

Enter the key elememts

100

Element 100  not found

Menu

1.linear search

2.binary search

3.exit

Enter your choice

3

[141740@localhost ~]$