Fibonacci Sequence

#include <stdio.h>
int main(void) {
    int first = 0, second = 1;
    for (int i = 0; i < 10; ++i) {
        printf("%s%d", i ? " " : "", first);
        // Advance the pair without storing the whole sequence.
        int next = first + second; first = second; second = next;
    }
    puts("");
}

#include <iostream>
int main() {
    int first = 0, second = 1;
    for (int i = 0; i < 10; ++i) {
        if (i) std::cout << ' ';
        std::cout << first;
        // Advance the pair without storing the whole sequence.
        int next = first + second; first = second; second = next;
    }
    std::cout << '\n';
}