Question

Write a program that receives a positive integer n from the user and then calculates the sum below by using a loop. Your program needs to ask the user to re-enter a different number if the user enters a non-positive one. Display the result. 1 SUM 1 2 3 ... n x x n = = = + + + +

Answer 1

Code:

#include<iostream>
using namespace std;
int main()
{
   int n,i,sum=0;
   cout<<"Enter a number to find the sum of numbers below it:";
   cin>>n;/*Reading number from the user*/
   while(n<=0)
   {/*This loop execute until user enter a positive number*/
       cout<<"Number should be positive"<<endl;
       cout<<"Enter a number to find the sum of numbers below it:";
       cin>>n;
   }
   for(i=1;i<=n;i++)
   {/*This loop iterates for 1 to n*/
       sum+=i;  
       /*Here we calculate the sum*/
   }
   cout<<"Sum is: "<<sum;
   /*Finall we print the sum*/
}

Output:

Enter a number to find the sum of numbers below it:-1 Number should be positive Enter a number to find the sum of numbers below it:-2 Number should be positive Enter a number to find the sum of numbers below it:100 Sum is: 5050

indentation:

#include<iostream> using namespace std; int main() { int n, i, sum=0; cout<<"Enter a number to find the sum of numbers below it:"; cin>>n; /*Reading number from the user*/ while(n<=0) {/*This Loop execute until user enter a positive number*/ cout<<"Number should be positive"<<endl; cout<<"Enter a number to find the sum of numbers below it:"; cin>>n; } for(i=1;i<=n; i++) {/*This Loop iterates for 1 to n*/ sumuri; /*Here we calculate the sum*/ } cout<<"Sum is: "<<sum; /*Finall we print the sum* i }