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, and - The amount of money withdrawn or transferred from is less than or equal to the balance of the account.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: Simulation
Time complexity: O(1) per operation
Space complexity: O(n) for n accounts
C++
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class Bank { public: Bank(vector<long long>& balance) : n_(balance.size()), balance_(balance) {} bool transfer(int account1, int account2, long long money) { if (account1 <= 0 || account1 > n_) return false; if (account2 <= 0 || account2 > n_) return false; if (balance_[account1 - 1] < money) return false; balance_[account1 - 1] -= money; balance_[account2 - 1] += money; return true; } bool deposit(int account, long long money) { if (account <= 0 || account > n_) return false; balance_[account - 1] += money; return true; } bool withdraw(int account, long long money) { if (account <= 0 || account > n_ || balance_[account - 1] < money) return false; balance_[account - 1] -= money; return true; } private: const int n_; vector<long long> balance_; }; /** * Your Bank object will be instantiated and called as such: * Bank* obj = new Bank(balance); * bool param_1 = obj->transfer(account1,account2,money); * bool param_2 = obj->deposit(account,money); * bool param_3 = obj->withdraw(account,money); */ |
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