# Link: https://leetcode.com/problems/min-stack/
from typing import List
import pytest


class MinStack:
    def __init__(self):
        self._s: List[int] = []
        self._min: List[int] = []

    def push(self, val: int) -> None:
        if len(self._s) == 0:
            self._min.append(0)
        elif val < self._s[self._min[-1]]:
            self._min.append(len(self._s))
        self._s.append(val)

    def pop(self) -> None:
        if len(self._s) - 1 == self._min[-1]:
            self._min.pop()
        self._s.pop()

    def top(self) -> int:
        return self._s[-1]

    def getMin(self) -> int:
        return self._s[self._min[-1]]


class TestSuite:
    @pytest.fixture(autouse=True)
    def init_tests(self):
        self.sol = MinStack()

    def test_solution_1(self):
        self.sol.push(1)
        self.sol.push(-1)
        self.sol.push(2)
        self.sol.push(-2)
        self.sol.pop()
        assert self.sol.getMin() == -1

    def test_solution_2(self):
        breakpoint()
        self.sol.push(-2)
        self.sol.push(0)
        self.sol.push(-1)
        assert self.sol.getMin() == -2
        assert self.sol.top() == -1
        self.sol.pop()
        assert self.sol.getMin() == -2