Inventory Manager

Lab Python Advanced 30 points

Manage a shop inventory with commands: add ITEM QTY PRICE, sell ITEM QTY (print not enough ITEM if short), report (print each item sorted as ITEM QTY @ PRICE with 2-decimal price, then value: TOTAL).

Input

Line 1: n. Then n commands.

Output

The messages and reports.

Example

Input

6
add pen 10 1.5
add book 2 12
sell pen 4
sell book 3
add pen 5 1.75
report

Output

not enough book
book 2 @ 12.00
pen 11 @ 1.75
value: 43.25

Sample input available Sample output available

Editor

Python

Hints

Store items in a dict of small objects.

Handle each command in its own branch.

Solution explanation

Real programs are mostly this: a data structure plus a loop that applies commands to it.

Show solution

from dataclasses import dataclass


@dataclass
class Stock:
    qty: int
    price: float


inventory = {}
for _ in range(int(input())):
    cmd, *args = input().split()
    if cmd == "add":
        name, qty, price = args[0], int(args[1]), float(args[2])
        if name in inventory:
            inventory[name].qty += qty
            inventory[name].price = price
        else:
            inventory[name] = Stock(qty, price)
    elif cmd == "sell":
        name, qty = args[0], int(args[1])
        stock = inventory.get(name)
        if stock is None or stock.qty < qty:
            print(f"not enough {name}")
        else:
            stock.qty -= qty
    elif cmd == "report":
        for name in sorted(inventory):
            s = inventory[name]
            print(f"{name} {s.qty} @ {s.price:.2f}")
        print(f"value: {sum(s.qty * s.price for s in inventory.values()):.2f}")

Output

Answer