Please explain how answer of this program is 297

Question

#include <iostream>
using namespace std;

int main() {
int s=0;
int num1=7;
int num=24;
for(int i=1;num1<=num;i++)
{
if(i!=3){
}
num1++;
s=s+num1;

}
cout<<s;
return 0;
}

Answer 1

Iteration 1 : num1 = 8 and s = s + 8 = 0 + 8 = 8
Iteration 2 : num1 = 9 and s = s + 9 = 8 + 9 = 17
..................
Last Iteration : num1 = 25 and ..........

So, the result is nothing but the sum of numbers from 8 to 25 which is (sum from 1 to 25) - (sum from 1 to 7) which is (325) - (28) which is 297. I presume you know the formula for calculating sum of numbers from 1 to n which is (n)(n+1)/2.

Answer 2

Yeah, a typo. It's corrected now.

Answer 3

its (n)(n+1)/2 i think

Answer 4

we cant calculate sum of numbers from 8 to 25 by this formula.?