use rand::seq::SliceRandom; // shuffle
use rand::rng; // thread-local random generator (rand 0.9+)
/*
A standard deck of 52 playing cards consists of four suits:
spades (♠), hearts (♥), diamonds (♦), and clubs (♣).
Each suit contains 13 ranks:
Ace, 2, 3, 4, 5, 6, 7, 8, 9, 10, Jack, Queen, King.
Cards of spades and clubs are black, while hearts and diamonds are red.
Color is informational only — it does not affect shuffling or random selection.
*/
/*
This program performs multiple draws of 5 random cards from a 52‑card deck
WITHOUT duplicates across draws.
It uses:
- Vec<String> for the deck
- SliceRandom::shuffle for efficient randomization (Fisher–Yates internally)
- functions for clean structure
Algorithm:
1. Build a full deck (52 cards)
2. For each draw:
a. Shuffle the remaining deck
b. Draw 5 cards
c. Remove them from the deck
*/
fn build_deck() -> Vec<String> {
let ranks = vec![
"2","3","4","5","6","7","8","9","10","J","Q","K","A"
];
let suits = vec![
"Clubs", "Diamonds", "Hearts", "Spades"
];
let mut deck = Vec::with_capacity(52);
for suit in suits {
for rank in &ranks {
deck.push(format!("{} of {}", rank, suit));
}
}
deck
}
fn draw_five(deck: &mut Vec<String>, draw_number: usize) {
// Shuffle the remaining deck before this draw
let mut rng = rng();
deck.shuffle(&mut rng);
println!("Draw #{}:", draw_number);
for card in deck.iter().take(5) {
println!(" {}", card);
}
println!();
// Remove drawn cards
deck.drain(0..5);
}
fn main() {
// Number of draws
let number_of_draws = 3;
let mut deck = build_deck();
// Perform multiple draws (no duplicates)
for draw_index in 1..=number_of_draws {
if deck.len() < 5 {
println!("Not enough cards left for draw #{}.", draw_index);
break;
}
draw_five(&mut deck, draw_index);
}
}
/*
run:
Draw #1:
6 of Hearts
7 of Diamonds
K of Diamonds
10 of Clubs
2 of Diamonds
Draw #2:
3 of Spades
K of Hearts
2 of Hearts
5 of Hearts
8 of Hearts
Draw #3:
9 of Spades
J of Spades
3 of Clubs
9 of Hearts
Q of Diamonds
*/
