feat: Add sample for fair coin toss.

Author: goloroden

README.md

@@ -13,6 +13,7 @@ So far, the following exercises have been covered:
 - [Cons, Car, Cdr & co.](./cons) – implements a cons cell and the corresponding functions
 - [Continous maximum](./continuousmax/) – calculates the maximum of a sliding window
 - [Egyptian fractions](./egyptianfractions/) – calculates the "Egyptian Fractions" version of a given fraction
+- [Fair coin toss](./faircointoss/) – simulates a fair coin toss based on an unfair random function
 - [Fibonacci](./fibonacci/) – calculates the n-th Fibonacci number
 - [Floyd](./floyd/) – implements Floyd's cycle-finding "Tortoise and Hare" algorithm
 - [Heap](./heap/) – implements a heap from scratch, without using the built-in `container/heap` package

faircointoss/coin_side.go

@@ -0,0 +1,8 @@
+package faircointoss
+
+type CoinSide string
+
+const (
+	CoinSideHeads CoinSide = "heads"
+	CoinSideTails CoinSide = "tails"
+)

faircointoss/documentation.go

@@ -0,0 +1,2 @@
+// Package faircointoss simulates a fair coin toss based on an unfair random function.
+package faircointoss

faircointoss/fair.go

@@ -0,0 +1,14 @@
+package faircointoss
+
+func FairCoinToss() CoinSide {
+	for {
+		firstCoinSide := UnfairCoinToss()
+		secondCoinSide := UnfairCoinToss()
+
+		if firstCoinSide == secondCoinSide {
+			continue
+		}
+
+		return firstCoinSide
+	}
+}

faircointoss/unfair.go

@@ -0,0 +1,13 @@
+package faircointoss
+
+import "math/rand/v2"
+
+func UnfairCoinToss() CoinSide {
+	randomNumber := rand.Float64()
+
+	if randomNumber < 0.99 {
+		return CoinSideHeads
+	} else {
+		return CoinSideTails
+	}
+}