Question

C++ language. please provide detailed comments (for beginners) and use easy to understand/trace code.

Thank you

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A positive integer n is triangular if it can be obtained by the product of three consecutive
positive integers. Given n > 0, determine whether n is triangular.
For example, 120 is triangular, since 4 · 5 · 6 = 120.

Answer 1

#include <iostream>

using namespace std;

int main() {
    int n;
    cout << "Enter a number: "; // ask user for a number
    cin >> n;   // read a number from user
    for (int i = 1; i < n-2; ++i) { // loop i values from 1 to n-2
        if (i * (i+1) * (i+2) == n) {   // check if product of 3 consecutive numbers give a value of n
            cout << n << " is a triangular number" << endl; // if yes, print it's a triangular number
            return 0;   // and exit the number
        }
    }
    cout << n << " is not a triangular number" << endl; // print not a triangular number if it's not
    return 0;
}