2043. Simple Bank System
You have been tasked with writing a program for a popular bank that will automate all its incoming transactions (transfer, deposit, and withdraw). The bank has n
accounts numbered from 1
to n
. The initial balance of each account is stored in a 0-indexed integer array balance
, with the (i + 1)th
account having an initial balance of balance[i]
.
Execute all the valid transactions. A transaction is valid if:
The given account number(s) are between
1
andn
, andThe amount of money withdrawn or transferred from is less than or equal to the balance of the account.
Implement the Bank
class:
Bank(long[] balance)
Initializes the object with the 0-indexed integer arraybalance
.boolean transfer(int account1, int account2, long money)
Transfersmoney
dollars from the account numberedaccount1
to the account numberedaccount2
. Returntrue
if the transaction was successful,false
otherwise.boolean deposit(int account, long money)
Depositmoney
dollars into the account numberedaccount
. Returntrue
if the transaction was successful,false
otherwise.boolean withdraw(int account, long money)
Withdrawmoney
dollars from the account numberedaccount
. Returntrue
if the transaction was successful,false
otherwise.
Example 1:
Input
["Bank", "withdraw", "transfer", "deposit", "transfer", "withdraw"]
[[[10, 100, 20, 50, 30]], [3, 10], [5, 1, 20], [5, 20], [3, 4, 15], [10, 50]]
Output
[null, true, true, true, false, false]
Explanation
Bank bank = new Bank([10, 100, 20, 50, 30]);
bank.withdraw(3, 10); // return true, account 3 has a balance of $20, so it is valid to withdraw $10.
// Account 3 has $20 - $10 = $10.
bank.transfer(5, 1, 20); // return true, account 5 has a balance of $30, so it is valid to transfer $20.
// Account 5 has $30 - $20 = $10, and account 1 has $10 + $20 = $30.
bank.deposit(5, 20); // return true, it is valid to deposit $20 to account 5.
// Account 5 has $10 + $20 = $30.
bank.transfer(3, 4, 15); // return false, the current balance of account 3 is $10,
// so it is invalid to transfer $15 from it.
bank.withdraw(10, 50); // return false, it is invalid because account 10 does not exist.
Constraints:
n == balance.length
1 <= n, account, account1, account2 <= 105
0 <= balance[i], money <= 1012
At most
104
calls will be made to each functiontransfer
,deposit
,withdraw
.
分析: 注意Index从1 开始,只需要判断1<=account<=n
class Bank:
def __init__(self, balance: List[int]):
self.balance = balance
self.n = len(self.balance)
def transfer(self, account1: int, account2: int, money: int) -> bool:
if 1<= account1 <= self.n and 1 <= account2 <= self.n and self.balance[account1-1] >= money:
self.balance[account1-1] -= money
self.balance[account2-1] += money
return True
return False
def deposit(self, account: int, money: int) -> bool:
if 1<= account <= self.n:
self.balance[account-1] += money
return True
return False
def withdraw(self, account: int, money: int) -> bool:
if 1<= account <= self.n and money <= self.balance[account-1]:
self.balance[account-1] -= money
return True
return False
# Your Bank object will be instantiated and called as such:
# obj = Bank(balance)
# param_1 = obj.transfer(account1,account2,money)
# param_2 = obj.deposit(account,money)
# param_3 = obj.withdraw(account,money)
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