Write a C++ Program to find the sum of natural numbers from 1 to n. This C++ program allows you to enter the maximum number to calculate the sum of natural numbers. Next, we used the while loop to iterate from 1 to n by incrementing the i value. Within the loop, we are adding each value of i to the sum and prints the sum.
#include<iostream>
using namespace std;
int main()
{
int number, i = 1, sum = 0;
cout << "\nPlease Enter the Number to find Sum of Natural Num = ";
cin >> number;
while( i <= number)
{
sum = sum + i;
i++;
}
cout << "\nThe Sum of Natural Number from 1 to " << number << " = " << sum;
return 0;
}
C++ Sum of Natural Numbers example code using Do While Loop.
#include<iostream>
using namespace std;
int main()
{
int number, i = 1, sum = 0;
cout << "\nPlease Enter the Number to find Sum of Natural Num = ";
cin >> number;
do
{
sum = sum + i;
i++;
} while( i <= number);
cout << "\nThe Sum of Natural Number from 1 to " << number << " = " << sum;
return 0;
}
C++ Program to find Sum of Natural Numbers using For Loop
Here, we added one more cout statement inside the for loop: cout << “\n Iteration = ” << i << “, i = ” << i << “, sum = “<< sum << ” + ” << i << ” = “<< sum + i;. This statement helps you to understand the program in iteration wise.
#include<iostream>
using namespace std;
int main()
{
int number, i = 1, sum = 0;
cout << "\nPlease Enter the Number to find Sum of Natural Num = ";
cin >> number;
for(i = 1; i <= number; i++)
{
cout << "\n Iteration = " << i << ", i = " << i << ", sum = "<< sum << " + " << i << " = "<< sum + i;
sum = sum + i;
}
cout << "\nThe Sum of Natural Number from 1 to " << number << " = " << sum;
return 0;
}
C++ Program to calculate the Sum of Natural Numbers using Functions.
#include<iostream>
using namespace std;
int sumOfNaturalNumbers(int number)
{
int sum = 0;
for(int i = 1; i <= number; i++)
{
sum = sum + i;
}
return sum;
}
int main()
{
int number;
cout << "\nPlease Enter the Number to find Sum of Natural Num = ";
cin >> number;
int sum = sumOfNaturalNumbers(number);
cout << "\nThe Sum of Natural Number from 1 to " << number << " = " << sum;
return 0;
}
C++ Program to Calculate the Sum of Natural Numbers using a Math formula
As we all know, the mathematical formula to calculate the sum of natural numbers = number * (number + 1) / 2).
#include<iostream>
using namespace std;
int sumOfNaturalNumbers(int number)
{
if(number == 0)
{
return number;
}
else
{
return (number * (number + 1) / 2);
}
}
int main()
{
int number;
cout << "\nPlease Enter the Number to find Sum of Natural Num = ";
cin >> number;
int sum = sumOfNaturalNumbers(number);
cout << "\nThe Sum of Natural Number from 1 to " << number << " = " << sum;
return 0;
}
C++ Program to Calculate the Sum of Natural Numbers using Recursion.
#include<iostream>
using namespace std;
int sumOfNaturalNumbers(int number)
{
if(number == 0)
{
return number;
}
else
{
return (number + sumOfNaturalNumbers(number - 1));
}
}
int main()
{
int number;
cout << "\nPlease Enter the Number to find Sum of Natural Num = ";
cin >> number;
int sum = sumOfNaturalNumbers(number);
cout << "\nThe Sum of Natural Number from 1 to " << number << " = " << sum;
return 0;
}