Write a program that prints the sum of the first five positive integers ,1+2+.....+5.

Answer 1

#include <iostream>
using std::cout;

int main() {
int sum = 0;
int A1 = 1;
int An = 5;
for(int i = A1; i <= An; ++i)
sum += i;
cout << sum;
}

Answer 2

Or ( Sn = (A1 + An) / 2 * n) ) — sum of algebraic progression

#include <iostream>
using std::cout;

int main() {
int A1 = 1;
int An = 5;
int n = 5;
int sum = float(A1 + An) / 2 * n;
cout << sum;
}

Answer 3

thank you for answering

Answer 4

Why not use Gaussian summation formula in the form it is taught in school? (n(n+1))/2

#include <iostream>
using namespace std;

int gauss(int);

int main(){
int n;
cin >> n;

cout << gauss(n) << endl;
}

int gauss(int m){
return (m * (m + 1)) / 2;
}