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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
1andn, and - The amount of money withdrawn or transferred from is less than or equal to the balance of the account.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)Transfersmoneydollars from the account numberedaccount1to the account numberedaccount2. Returntrueif the transaction was successful,falseotherwise.boolean deposit(int account, long money)Depositmoneydollars into the account numberedaccount. Returntrueif the transaction was successful,falseotherwise.boolean withdraw(int account, long money)Withdrawmoneydollars from the account numberedaccount. Returntrueif the transaction was successful,falseotherwise.
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.length1 <= n, account, account1, account2 <= 1050 <= balance[i], money <= 1012- At most
104calls will be made to each functiontransfer,deposit,withdraw.
Solution 1.
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// 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; } }; -
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) -
class Bank { private long[] balance; private int n; public Bank(long[] balance) { this.balance = balance; this.n = balance.length; } public boolean transfer(int account1, int account2, long money) { if (account1 > n || account2 > n || balance[account1 - 1] < money) { return false; } balance[account1 - 1] -= money; balance[account2 - 1] += money; return true; } public boolean deposit(int account, long money) { if (account > n) { return false; } balance[account - 1] += money; return true; } public boolean withdraw(int account, long money) { if (account > n || balance[account - 1] < money) { return false; } balance[account - 1] -= money; return true; } } /** * Your Bank object will be instantiated and called as such: * Bank obj = new Bank(balance); * boolean param_1 = obj.transfer(account1,account2,money); * boolean param_2 = obj.deposit(account,money); * boolean param_3 = obj.withdraw(account,money); */ -
type Bank struct { balance []int64 n int } func Constructor(balance []int64) Bank { return Bank{balance, len(balance)} } func (this *Bank) Transfer(account1 int, account2 int, money int64) bool { if account1 > this.n || account2 > this.n || this.balance[account1-1] < money { return false } this.balance[account1-1] -= money this.balance[account2-1] += money return true } func (this *Bank) Deposit(account int, money int64) bool { if account > this.n { return false } this.balance[account-1] += money return true } func (this *Bank) Withdraw(account int, money int64) bool { if account > this.n || this.balance[account-1] < money { return false } this.balance[account-1] -= money return true } /** * Your Bank object will be instantiated and called as such: * obj := Constructor(balance); * param_1 := obj.Transfer(account1,account2,money); * param_2 := obj.Deposit(account,money); * param_3 := obj.Withdraw(account,money); */ -
class Bank { balance: number[]; constructor(balance: number[]) { this.balance = balance; } transfer(account1: number, account2: number, money: number): boolean { if ( account1 > this.balance.length || account2 > this.balance.length || money > this.balance[account1 - 1] ) return false; this.balance[account1 - 1] -= money; this.balance[account2 - 1] += money; return true; } deposit(account: number, money: number): boolean { if (account > this.balance.length) return false; this.balance[account - 1] += money; return true; } withdraw(account: number, money: number): boolean { if ( account > this.balance.length || money > this.balance[account - 1] ) { return false; } this.balance[account - 1] -= money; return true; } } /** * Your Bank object will be instantiated and called as such: * var obj = new Bank(balance) * var param_1 = obj.transfer(account1,account2,money) * var param_2 = obj.deposit(account,money) * var param_3 = obj.withdraw(account,money) */ -
struct Bank { balance: Vec<i64>, } /** * `&self` means the method takes an immutable reference. * If you need a mutable reference, change it to `&mut self` instead. */ impl Bank { fn new(balance: Vec<i64>) -> Self { Bank { balance } } fn transfer(&mut self, account1: i32, account2: i32, money: i64) -> bool { let (account1, account2, n) = (account1 as usize, account2 as usize, self.balance.len()); if n < account1 || n < account2 { return false; } if self.balance[account1 - 1] < money { return false; } self.balance[account1 - 1] -= money; self.balance[account2 - 1] += money; true } fn deposit(&mut self, account: i32, money: i64) -> bool { let (account, n) = (account as usize, self.balance.len()); if n < account { return false; } self.balance[account - 1] += money; true } fn withdraw(&mut self, account: i32, money: i64) -> bool { let (account, n) = (account as usize, self.balance.len()); if n < account { return false; } if self.balance[account - 1] < money { return false; } self.balance[account - 1] -= money; true } } /** * Your Bank object will be instantiated and called as such: * let obj = Bank::new(balance); * let ret_1: bool = obj.transfer(account1, account2, money); * let ret_2: bool = obj.deposit(account, money); * let ret_3: bool = 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); } -
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) -
class Bank { private long[] balance; private int n; public Bank(long[] balance) { this.balance = balance; this.n = balance.length; } public boolean transfer(int account1, int account2, long money) { if (account1 > n || account2 > n || balance[account1 - 1] < money) { return false; } balance[account1 - 1] -= money; balance[account2 - 1] += money; return true; } public boolean deposit(int account, long money) { if (account > n) { return false; } balance[account - 1] += money; return true; } public boolean withdraw(int account, long money) { if (account > n || balance[account - 1] < money) { return false; } balance[account - 1] -= money; return true; } } /** * Your Bank object will be instantiated and called as such: * Bank obj = new Bank(balance); * boolean param_1 = obj.transfer(account1,account2,money); * boolean param_2 = obj.deposit(account,money); * boolean param_3 = obj.withdraw(account,money); */ -
type Bank struct { balance []int64 n int } func Constructor(balance []int64) Bank { return Bank{balance, len(balance)} } func (this *Bank) Transfer(account1 int, account2 int, money int64) bool { if account1 > this.n || account2 > this.n || this.balance[account1-1] < money { return false } this.balance[account1-1] -= money this.balance[account2-1] += money return true } func (this *Bank) Deposit(account int, money int64) bool { if account > this.n { return false } this.balance[account-1] += money return true } func (this *Bank) Withdraw(account int, money int64) bool { if account > this.n || this.balance[account-1] < money { return false } this.balance[account-1] -= money return true } /** * Your Bank object will be instantiated and called as such: * obj := Constructor(balance); * param_1 := obj.Transfer(account1,account2,money); * param_2 := obj.Deposit(account,money); * param_3 := obj.Withdraw(account,money); */ -
class Bank { balance: number[]; constructor(balance: number[]) { this.balance = balance; } transfer(account1: number, account2: number, money: number): boolean { if ( account1 > this.balance.length || account2 > this.balance.length || money > this.balance[account1 - 1] ) return false; this.balance[account1 - 1] -= money; this.balance[account2 - 1] += money; return true; } deposit(account: number, money: number): boolean { if (account > this.balance.length) return false; this.balance[account - 1] += money; return true; } withdraw(account: number, money: number): boolean { if ( account > this.balance.length || money > this.balance[account - 1] ) { return false; } this.balance[account - 1] -= money; return true; } } /** * Your Bank object will be instantiated and called as such: * var obj = new Bank(balance) * var param_1 = obj.transfer(account1,account2,money) * var param_2 = obj.deposit(account,money) * var param_3 = obj.withdraw(account,money) */ -
struct Bank { balance: Vec<i64>, } /** * `&self` means the method takes an immutable reference. * If you need a mutable reference, change it to `&mut self` instead. */ impl Bank { fn new(balance: Vec<i64>) -> Self { Bank { balance } } fn transfer(&mut self, account1: i32, account2: i32, money: i64) -> bool { let (account1, account2, n) = (account1 as usize, account2 as usize, self.balance.len()); if n < account1 || n < account2 { return false; } if self.balance[account1 - 1] < money { return false; } self.balance[account1 - 1] -= money; self.balance[account2 - 1] += money; true } fn deposit(&mut self, account: i32, money: i64) -> bool { let (account, n) = (account as usize, self.balance.len()); if n < account { return false; } self.balance[account - 1] += money; true } fn withdraw(&mut self, account: i32, money: i64) -> bool { let (account, n) = (account as usize, self.balance.len()); if n < account { return false; } if self.balance[account - 1] < money { return false; } self.balance[account - 1] -= money; true } } /** * Your Bank object will be instantiated and called as such: * let obj = Bank::new(balance); * let ret_1: bool = obj.transfer(account1, account2, money); * let ret_2: bool = obj.deposit(account, money); * let ret_3: bool = obj.withdraw(account, money); */
Discuss
https://leetcode.com/problems/simple-bank-system/discuss/1525207/C%2B%2B-Straightforward