package main
import (
"fmt"
"math/rand"
"time"
)
/*
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:
- slices of strings for the deck
- rand.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
*/
func buildDeck() []string {
ranks := []string{"2","3","4","5","6","7","8","9","10","J","Q","K","A"}
suits := []string{"Clubs", "Diamonds", "Hearts", "Spades"}
deck := make([]string, 0, 52)
for _, suit := range suits {
for _, rank := range ranks {
deck = append(deck, rank+" of "+suit)
}
}
return deck
}
func shuffleDeck(deck []string) {
rand.Shuffle(len(deck), func(i, j int) {
deck[i], deck[j] = deck[j], deck[i]
})
}
func drawFive(deck []string, drawNumber int) []string {
// Shuffle the remaining deck before this draw
shuffleDeck(deck)
fmt.Printf("Draw #%d:\n", drawNumber)
for i := 0; i < 5; i++ {
fmt.Println(" ", deck[i])
}
fmt.Println()
// Remove drawn cards
return deck[5:]
}
func main() {
rand.Seed(time.Now().UnixNano())
// Number of draws
draws := 3
deck := buildDeck()
// Perform multiple draws (no duplicates)
for drawIndex := 1; drawIndex <= draws; drawIndex++ {
if len(deck) < 5 {
fmt.Printf("Not enough cards left for draw #%d.\n", drawIndex)
break
}
deck = drawFive(deck, drawIndex)
}
}
/*
run:
Draw #1:
K of Clubs
7 of Clubs
2 of Diamonds
5 of Clubs
A of Hearts
Draw #2:
J of Diamonds
4 of Diamonds
J of Spades
5 of Diamonds
3 of Hearts
Draw #3:
3 of Clubs
A of Clubs
Q of Diamonds
Q of Clubs
J of Hearts
*/
