Answer:
This c++ program swaps the first and last elements of the array.
#include <iostream>
using namespace std;
void SwapArrayEnds(int a[], int k);
int main() {
int len, arr[len];
int j;
cout<<"Enter the size of array" <<endl;
cin>>len;
cout<<"Enter the elements of the array"<<endl;
for(j=0; j<len; j++)
{
cin>>arr[j];
}
cout<<"The elements of the array before swapping are"<<endl;
for(j=0; j<len; j++)
{
cout<<arr[j]<<"\t";
}
SwapArrayEnds(arr, len);
return 0;
}
void SwapArrayEnds(int a[], int k)
{
int temp=a[0];
int l;
a[0]=a[k-1];
a[k-1]=temp;
cout<<endl<<"The elements of the array after swapping are"<<endl;
for(l=0; l<k; l++)
{
cout<<a[l]<<"\t";
}
}
OUTPUT
Enter the size of array
6
Enter the elements of the array
12
34
56
78
90
23
The elements of the array before swapping are
12 34 56 78 90 23
The elements of the array after swapping are
23 34 56 78 90 12
Explanation:
This program accepts user input for both size and elements of the array.
The first and the last element of the array are swapped in another method, SwapArrayEnds.
This method accepts an integer array and another integer variable which shows the size of the array.
The method which accepts parameters is declared as shown.
void SwapArrayEnds(int a[], int k);
In the above declaration, void is the return type. The parameter list contains one integer array followed by the length of that array.
This method is defined as below.
void SwapArrayEnds(int a[], int k)
{
// first element of the array is assigned to another variable
int temp=a[0];
int l;
// last element of the array is assigned to the first index, 0, of the array
a[0]=a[k-1];
// last index of the array is assigned the original first element of the array copied in temp
a[k-1]=temp;
cout<<endl<<"The elements of the array after swapping are"<<endl;
for(l=0; l<k; l++)
{
cout<<a[l]<<"\t";
}
}
