main.go

package main

import (
	"fmt"
	"sync"
	"sync/atomic"
)

// conversionFactor is used to scale values by 1000 to preserve precision during float64 to int64 conversion.
const conversionFactor int64 = 1000

type Account struct {
	balance int64 // Balance stored in "scaled integer format" (e.g., 50.123 is stored as 50123)
}

// GetRawBalance returns the balance as an int64 value in its scaled format (internal representation).
func (a *Account) GetRawBalance() int64 {
	return atomic.LoadInt64(&a.balance)
}

// GetBalance returns the balance as a float64 value for external use (converted from the scaled format).
func (a *Account) GetBalance() float64 {
	return float64(a.GetRawBalance()) / float64(conversionFactor)
}

// Deposit adds an amount (in float64) to the account balance.
func (a *Account) Deposit(amount float64) {
	scaleAmount := int64(amount * float64(conversionFactor))
	atomic.AddInt64(&a.balance, scaleAmount)
}

// Withdraw attempts to subtract an amount (in float64) from the account balance atomically.
// Returns true if the withdrawal is successful, or false if there are insufficient funds.
func (a *Account) WithDraw(amount float64) bool {
	scaleAmount := int64(amount * float64(conversionFactor))

	for {
		currentBalance := a.GetRawBalance()
		if currentBalance < scaleAmount {
			return false
		}

		if atomic.CompareAndSwapInt64(&currentBalance, currentBalance, scaleAmount) {
			return true
		}
	}
}


func main() {
	var wg sync.WaitGroup
	account := &Account{}
	numGoroutines := 5

	// Goroutines for deposits
	for i := 0; i < numGoroutines; i++ {
		wg.Add(1)
		go func(id int) {
			defer wg.Done()
			amount := float64(id) * 10.25
			beforeBalance := account.GetBalance()
			account.Deposit(amount)
			afterBalance := account.GetBalance()
			fmt.Printf("->[%d]: Deposited %.2f | Before: %.2f, After: %.2f\n", id, amount, beforeBalance, afterBalance)
		}(i)
	}

	// Goroutines for withdrawals
	for i := 0; i < numGoroutines; i++ {
		wg.Add(1)
		go func(id int) {
			defer wg.Done()
			amount := float64(id) * 15.50
			beforeBalance := account.GetBalance()
			if success := account.WithDraw(amount); success {
				afterBalance := account.GetBalance()
				fmt.Printf("<-[%d]: Successfully withdrew %.2f | Before: %.2f, After: %.2f\n", id, amount, beforeBalance, afterBalance)
			} else {
				fmt.Printf("<-[%d]: Failed to withdraw %.2f (Insufficient funds) | Balance: %.2f\n", id, amount, beforeBalance)
			}
		}(i)
	}

	wg.Wait()
	fmt.Printf("Final account balance: %.2f\n", account.GetBalance())
}