Example: Fibonacci Sequence up to Nth Term in C++

// Fibonacci Sequence up to Nth Term
#include <iostream>
using namespace std;

int main() {
    // Step 1: Declare variables
    int n;           // Stores the desired number of terms
    int firstTerm = 0;   // Initialize the first Fibonacci term
    int secondTerm = 1;  // Initialize the second Fibonacci term
    int nextTerm;    // To store the sum of the previous two terms

    // Step 2: Prompt user for input
    cout << "Enter the number of terms (n) for Fibonacci sequence: ";
    cin >> n;

    // Step 3: Handle edge cases for n
    if (n < 0) {
        cout << "Please enter a non-negative integer." << endl;
    } else if (n == 0) {
        cout << "Fibonacci sequence up to 0 terms: " << endl;
    } else if (n == 1) {
        cout << "Fibonacci sequence up to 1 term: " << endl;
        cout << firstTerm << " ";
    } else {
        // Step 4: Print the first two terms
        cout << "Fibonacci sequence up to " << n << " terms: " << endl;
        cout << firstTerm << " " << secondTerm << " ";

        // Step 5: Loop to calculate and print subsequent terms
        for (int i = 3; i <= n; ++i) { // Loop starts from the 3rd term
            nextTerm = firstTerm + secondTerm; // Calculate the next term
            cout << nextTerm << " ";          // Print the next term
            firstTerm = secondTerm;            // Update firstTerm to the previous secondTerm
            secondTerm = nextTerm;             // Update secondTerm to the newly calculated nextTerm
        }
        cout << endl; // New line after printing the sequence
    }

    return 0;
}