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Formatted question description: https://leetcode.ca/all/2043.html
2043. Simple Bank System (Medium)
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
, and - The amount of money withdrawn or transferred from is less than or equal to the balance of the account.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
.
Solution 1.
-
// OJ: https://leetcode.com/problems/simple-bank-system/ // Time: O(1) for all // Space: O(N) class Bank { vector<long long> balance; bool valid(int account) { return account > 0 && account <= balance.size(); } bool enough(int account, long long money) { return balance[account - 1] >= money; } public: Bank(vector<long long>& balance) : balance(balance) {} bool transfer(int from, int to, long long money) { if (valid(from) && valid(to) && enough(from, money)) { balance[from - 1] -= money; balance[to - 1] += money; return true; } return false; } bool deposit(int account, long long money) { if (valid(account)) { balance[account - 1] += money; return true; } return false; } bool withdraw(int account, long long money) { if (valid(account) && enough(account, money)) { balance[account - 1] -= money; return true; } return false; } };
-
// Todo
-
class Bank: def __init__(self, balance: List[int]): self.balance = balance self.n = len(balance) def transfer(self, account1: int, account2: int, money: int) -> bool: if account1 > self.n or account2 > self.n or self.balance[account1 - 1] < money: return False self.balance[account1 - 1] -= money self.balance[account2 - 1] += money return True def deposit(self, account: int, money: int) -> bool: if account > self.n: return False self.balance[account - 1] += money return True def withdraw(self, account: int, money: int) -> bool: if account > self.n or self.balance[account - 1] < money: return False self.balance[account - 1] -= money return True # 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) ############ # 2043. Simple Bank System # https://leetcode.com/problems/simple-bank-system/ class Bank: def __init__(self, balance: List[int]): self.banks = [0] + balance self.n = len(balance) def transfer(self, account1: int, account2: int, money: int) -> bool: if 1 <= account1 <= self.n and 1 <= account2 <= self.n and self.banks[account1] >= money: self.banks[account1] -= money self.banks[account2] += money return True return False def deposit(self, account: int, money: int) -> bool: if 1 <= account <= self.n: self.banks[account] += money return True return False def withdraw(self, account: int, money: int) -> bool: if 1 <= account <= self.n and self.banks[account] >= money: self.banks[account] -= 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)
We can also implement transfer
using withdraw
and deposit
.
-
bool transfer(int from, int to, long long money) { return valid(to) && withdraw(from, money) && deposit(to, money); }
-
// Todo
-
class Bank: def __init__(self, balance: List[int]): self.balance = balance self.n = len(balance) def transfer(self, account1: int, account2: int, money: int) -> bool: if account1 > self.n or account2 > self.n or self.balance[account1 - 1] < money: return False self.balance[account1 - 1] -= money self.balance[account2 - 1] += money return True def deposit(self, account: int, money: int) -> bool: if account > self.n: return False self.balance[account - 1] += money return True def withdraw(self, account: int, money: int) -> bool: if account > self.n or self.balance[account - 1] < money: return False self.balance[account - 1] -= money return True # 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) ############ # 2043. Simple Bank System # https://leetcode.com/problems/simple-bank-system/ class Bank: def __init__(self, balance: List[int]): self.banks = [0] + balance self.n = len(balance) def transfer(self, account1: int, account2: int, money: int) -> bool: if 1 <= account1 <= self.n and 1 <= account2 <= self.n and self.banks[account1] >= money: self.banks[account1] -= money self.banks[account2] += money return True return False def deposit(self, account: int, money: int) -> bool: if 1 <= account <= self.n: self.banks[account] += money return True return False def withdraw(self, account: int, money: int) -> bool: if 1 <= account <= self.n and self.banks[account] >= money: self.banks[account] -= 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)
Discuss
https://leetcode.com/problems/simple-bank-system/discuss/1525207/C%2B%2B-Straightforward