Helpful self-assigned tasks & reference implementation when learning programming languages
Some of these tasks may exceed the limits of the language.
Construct and iterate over a container (list or vector) of structures using as less code as possible. For example, in C++ 17 ...
#include <iostream>
#include <vector>
struct person {
std::string name;
int age;
char gender;
};
int main() {
std::vector<person> group = {
{ "Alice", 20, 'F' },
{ "Bob", 21, 'M' },
{ "Cindy", 22, 'F' },
};
for (const auto &[name, age, gender] : group) {
std::cout << name << " " << age << " " << gender << std::endl;
}
}... or in Rust ...
struct Person {
name: std::string::String,
age: i32,
gender: char,
}
fn main() {
let group = vec![
Person {name: String::from("Alice"), age: 20, gender: 'F'},
Person {name: String::from("Bob"), age: 21, gender: 'M'},
Person {name: String::from("Cindy"), age: 22, gender: 'F'},
];
for Person {name, age, gender} in group {
println!("{} {} {}", name, age, gender)
}
}Construct a closure that computes the n-th fibonacci number using recursive algorithm.
Please note that, in some languages, recursive closure may not be posible.
#include <iostream>
#include <functional>
int main() {
std::function<int(int)> fib = [&fib](int i) -> int {
return (i <= 2) ? 1 : fib(i - 1) + fib(i - 2);
};
for (int i = 1; i <= 10; i++) {
std::cout << "fib(" << i << ")=" << fib(i) << std::endl;
}
return 0;
}#include <iostream>
#include <functional>
int main() {
// this code can be simplified using the non-standard compound literals
// however, compound-literals is forbidden by ISO C++
struct fib_generator {
int operator()(int n) {
return (n < 2) ? n : (*this)(n-1) + (*this)(n-2);
}
};
std::function<int(int)> fib = fib_generator {};
for (int i = 1; i <= 10; i++) {
std::cout << "fib(" << i << ")=" << fib(i) << std::endl;
}
return 0;
}