I want to write a program to simulate a vending machine and calculate the change (which has to be returned to you) based on the amount paid. Given the cost, the user should first be prompted to add more money until the cost is met/exceeded by the payment. Assume that all change is given in coins only and coins come in the following denominations: 1c, 5c, 10c, 25c, $1 Here is my program:
x = eval(input("Enter the cost (in cents):\n")) b = 0 for i in range(x+500): if x=b: b += 1 print("Deposit a coin or note (in cents):") print(1) diff = b-x for i in range(diff): onecents = diff//1 new_onecents = diff - (onecents*1) print("Your change is:") if onecents != 0: print(onecents,"x 1c") break elif x=b: b += 5 print("Deposit a coin or note (in cents):") print(5) diff = b-x for i in range(diff): fivecents = diff//5 new_fivecents = diff - (fivecents*5) onecents = new_fivecents//1 new_onecents = new_fivecents - (onecents*1) print("Your change is:") if fivecents != 0: print(fivecents,"x 5c") if onecents != 0: print(onecents,"x 1c") break elif x=b: b += 10 print("Deposit a coin or note (in cents):") print(10) diff = b-x for i in range(diff): tencents = diff//10 new_tencents = diff - (tencents*10) fivecents = new_tencents//5 new_fivecents = new_tencents - (fivecents*5) onecents = new_fivecents//1 new_onecents = new_fivecents - (onecents*1) print("Your change is:") if tencents !=0: print(tencents,"x 10c") if fivecents != 0: print(fivecents,"x 5c") if onecents != 0: print(onecents,"x 1c") break elif x=b: b += 25 print("Deposit a coin or note (in cents):") print(25) diff= b-x for i in range(diff): quarters = diff//25 new_quarters = diff - (quarters*25) tencents = new_quarters//10 new_tencents = new_quarters - (tencents*10) fivecents = new_tencents//5 new_fivecents = new_tencents - (fivecents*5) onecents = new_fivecents//1 new_onecents = new_fivecents - (onecents*1) print("Your change is:") if quarters !=0: print(quarters,"x 25c") if tencents !=0: print(tencents,"x 10c") if fivecents != 0: print(fivecents,"x 5c") if onecents != 0: print(onecents,"x 1c") break elif xb: print("Deposit a coin or note (in cents):") print(100) b += 100 diff = b-x for i in range(diff): quarters = diff//25 new_quarters = diff - (quarters*25) tencents = new_quarters//10 new_tencents = new_quarters - (tencents*10) fivecents = new_tencents//5 new_fivecents = new_tencents - (fivecents*5) onecents = new_fivecents//1 new_onecents = new_fivecents - (onecents*1) print("Your change is:") if quarters !=0: print(quarters,"x 25c") if tencents !=0: print(tencents,"x 10c") if fivecents != 0: print(fivecents,"x 5c") if onecents != 0: print(onecents,"x 1c") break elif x=b: print("Deposit a coin or note (in cents):") print(500) b += 500 diff = b-x for i in range(diff): onedollars = diff//100 new_onedollars = diff - (onedollars * 100) quarters = new_onedollars//25 new_quarters = new_onedollars - (quarters*25) tencents = new_quarters//10 new_tencents = new_quarters - (tencents*10) fivecents = new_tencents//5 new_fivecents = new_tencents - (fivecents*5) onecents = new_fivecents//1 new_onecents = new_fivecents - (onecents*1) print("Your change is:") if onedollars != 0: print(onedollars,"x $1") if quarters !=0: print(quarters,"x 25c") if tencents !=0: print(tencents,"x 10c") if fivecents != 0: print(fivecents,"x 5c") if onecents != 0: print(onecents,"x 1c") break
When I run this program and I follow the instructions it should look like this:
Enter the cost (in cents): 1000 Deposit a coin or note (in cents): 500 Deposit a coin or note (in cents): 500 Deposit a coin or note (in cents): Enter the cost (in cents): 1000 Deposit a coin or note (in cents): 500 Deposit a coin or note (in cents): 500 Deposit a coin or note (in cents): 500 Your change is: 5 x $1 Enter the cost (in cents): 3 Deposit a coin or note (in cents): 1 Deposit a coin or note (in cents): 1 Deposit a coin or note (in cents): 1 Enter the cost (in cents): 3 Deposit a coin or note (in cents): 1 Deposit a coin or note (in cents): 1 Deposit a coin or note (in cents): 1 Deposit a coin or note (in cents): 1 Your change is: 1 x 1c The rest does work out and is correct. Thanks for all your help guys (especially @jonrsharpe). Here is the solution (in code form):
def vend(): """Simulate a vending machine, taking user input and returning remainder.""" total = eval(input("Enter the cost (in cents):\n")) inserted = 0 while inserted < total: inserted += eval(input("Deposit a coin or note (in cents):\n")) if inserted >total: sum = inserted - total if sum != 0: print("Your change is:") dollars = sum//100 if dollars != 0: print(dollars,'x $1') quarters = (sum - dollars*100)//25 if quarters != 0: print(quarters,'x 25c') ten_cents = (sum - dollars*100 - quarters*25)//10 if ten_cents != 0: print(ten_cents,'x 10c') five_cents = (sum - dollars*100 - quarters*25 - ten_cents*10)//5 if five_cents != 0: print(five_cents,'x 5c') one_cents = (sum - dollars*100 - quarters*25 - ten_cents*10 - five_cents*5)//1 if one_cents != 0: print(one_cents,'x 1c') vend()