問題
Encapsulation keeps an object's data private and only changes it through methods that enforce the rules. A bank account's balance can only change through deposit and withdraw.
Start with a balance of 0 and process the operations, each deposit <amount> or withdraw <amount>:
- An amount that is 0 or negative is rejected.
- A withdrawal larger than the current balance is rejected.
- Otherwise the balance changes.
Implement bank_account_rules(operations).
Input
operations: The operations, in order.
Output
Return [final_balance, rejected_count].
制約
0 ≤ number of operations ≤ 100,000
−10^9 ≤ amount ≤ 10^9
例
入力：
operations = ["deposit 100", "withdraw 30", "withdraw 200"]
期待される出力：
expected = [70, 1]入力：
std::vector<std::string> operations = {"deposit 100", "withdraw 30", "withdraw 200"};
期待される出力：
std::vector<long long> expected = {70, 1};入力：
string[] operations = new string[] {"deposit 100", "withdraw 30", "withdraw 200"};
期待される出力：
long[] expected = new long[] {70, 1};解説
100 − 30 leaves 70; withdrawing 200 would overdraw the account, so it is rejected: [70, 1].
入力：
operations = ["deposit -5", "withdraw 0", "deposit 10"]
期待される出力：
expected = [10, 2]入力：
std::vector<std::string> operations = {"deposit -5", "withdraw 0", "deposit 10"};
期待される出力：
std::vector<long long> expected = {10, 2};入力：
string[] operations = new string[] {"deposit -5", "withdraw 0", "deposit 10"};
期待される出力：
long[] expected = new long[] {10, 2};解説
The negative deposit and the zero withdrawal are both rejected; the last deposit succeeds: [10, 2].
解き方のヒント
まずは自分で考えてから、ヒントを 1 つずつ開いてみましょう。
ヒント 1
Keep the balance private and change it only in deposit and withdraw.
ヒント 2
Reject amounts of 0 or less before anything else.
ヒント 3
A withdrawal may not take the balance below zero.
目安の計算量
O(number of operations) time, O(1) extra space
参考資料
この課題はCodeUtility用に調整されています。上記の説明と制約に従ってください。