Min Stack

A generic Stack<T> works for any type. Here you extend the idea: a stack of integers that can also report its minimum in constant time.

Process the operations in order:

• push <x>: push x.
• pop: remove the top value (ignored when the stack is empty).
• min: report the smallest value currently in the stack, or -1 if it is empty.

Implement min_stack_operations(operations).

Input

operations: The operations.

Output

Return the answers of the min operations, in order.

เงื่อนไข

1 ≤ number of operations ≤ 200,000

0 ≤ x ≤ 10^9

ตัวอย่าง

อินพุต:
operations = ["push 5", "push 3", "min", "pop", "min"]

ผลลัพธ์ที่คาดหวัง:
expected = [3, 5]

อินพุต:
std::vector<std::string> operations = {"push 5", "push 3", "min", "pop", "min"};

ผลลัพธ์ที่คาดหวัง:
std::vector<long long> expected = {3, 5};

อินพุต:
string[] operations = new string[] {"push 5", "push 3", "min", "pop", "min"};

ผลลัพธ์ที่คาดหวัง:
long[] expected = new long[] {3, 5};

อินพุต:
operations = ["min", "pop", "push 7", "min"]

ผลลัพธ์ที่คาดหวัง:
expected = [-1, 7]

อินพุต:
std::vector<std::string> operations = {"min", "pop", "push 7", "min"};

ผลลัพธ์ที่คาดหวัง:
std::vector<long long> expected = {-1, 7};

อินพุต:
string[] operations = new string[] {"min", "pop", "push 7", "min"};

ผลลัพธ์ที่คาดหวัง:
long[] expected = new long[] {-1, 7};

แหล่งอ้างอิง

โจทย์นี้ปรับให้เหมาะกับ CodeUtility กรุณาทำตามคำชี้แจงและข้อจำกัดด้านบน

• Microsoft Learn, C# documentation