Write c++ code to find the sum of all natural no from n to 1 using do while loop​

#include

using namespace std;

int main(){

  int n, sum=0;

  cout<<"Enter the value of n(should be a positive integer): ";  

  //Storing the input integer value into the variable n

  cin>>n;

  /* If user enters value of n as negative then display an  

   * error message to user that the value of n is invalid  

   */

  if(n<=0){

     cout<<"Invalid value of n";

  }

  else{

     // We are using while loop to calculate the sum

    int i=1;

    while(i<=n){

 sum=sum+i;

 i++;

    }

    cout<<"Sum of first n natural numbers is: "<<sum;

  }

  return 0;

}

Explanation: