Question

In C++

1. Write a program that allows a user to enter 10 integer values from the keyboard. The values should be stored in an array.

2. The program should then ask the user for a number to search for in the array:

• The program should use a binary search to determine if the number exists in a list of values that are stored in an array (from Step #1).
• If the user enters a number that is in the array, the program should display a message saying the number is valid.
• If the user enters a number not in the array, the program should display a message indicating it is invalid.

3. The program should also display the elements of the array on the screen:

• after the array is filled, and
• before the binary search is performed

4. The program should have a minimum of 3 functions (not including main), possible functions are:

• search function
• print function
• sort function
• fill array function
• etc.

Sample Run

Please enter 10 numbers:
12
23
45
65
78
98
41
21
54
87
The items entered into the array are:
12 23 45 65 78 98 41 21 54 87
The items in the array before the search:
12 21 23 41 45 54 65 78 87 98

What number do you want to search for?
45
the item was found at index: 4

Answer 1

//C++ code for performing binary search after sorting the given array

#include<iostream>
using namespace std;

void fill_array(int array[],int size) //function to fill array
{
for(int i=0;i<size;i++) //loop to read array elements
cin>>array[i];
}
void print_array(int array[],int size) //function to print array elements
{
for(int i=0;i<size;i++) //loop to display array elements
cout<<array[i]<<" ";

}
void sort (int array[], int size ) //function to sort the array
{
int temp;
for(int i=0;i<size;i++)
{
for(int j=i+1;j<size;j++)
{
if(array[i]>array[j]) //swap the adjacaet elements
{
temp=array[i];
array[i]=array[j];
array[j]=temp;
}
}
}
}
int binarySearch(int array[],int low,int high,int key)//function to search given number key
{
if (low<=high)
{
int mid=(low+high)/2;
  
if (array[mid]==key)
return mid;
  
else if(array[mid]>key)
return binarySearch(array,low,mid-1,key);
  
else
return binarySearch(array, mid + 1, high, key);
}
return -1;
}

int main()
{
int array[10],size=10,number,found;//declarations
  
cout<<"Please enter 10 numbers :"<<endl;
fill_array(array,size);
  
cout<<"\nThe items entered into the array are :"<<endl;
print_array(array,size);
  
cout<<"\nThe items in the array before search : "<<endl;
sort(array,size);//function to sort array elements to perform binary search
print_array(array,size);
  
cout<<"\nWhat number do you want to search for ? "<<endl; //to read number value
cin>>number;
int index = binarySearch(array,0,size-1,number);//function call
if(found==-1)
cout<<"The item was not found in the array";
else
cout<<"The item was found at index : "<<index;
return 0;

}