lst-0020-book.cpp
// https://godbolt.org/z/xcKM7v1Eo
#include <vector>
#include <iostream> // cout, endl
int main() {
std::vector qus{1,4,9,16,25};
for(unsigned idx=0; idx<qus.size(); ++idx) // size returns the count
std::cout << qus[idx] << " "; // [idx] or at(idx) gets an element
std::cout << std::endl;
}