QuickMinStackTest.java

package com.github.miniyk2012.coding2017.basic.stack;

import static org.junit.Assert.*;

import org.junit.After;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;

public class QuickMinStackTest {
    QuickMinStack stack;

    @Before
    public void setUp() throws Exception {
    }

    @After
    public void tearDown() throws Exception {
    }

    @Rule
    public ExpectedException expectedEx = ExpectedException.none();

    @Test
    public void test() {
        stack = new QuickMinStack<Integer>();

        stack.push(5);
        stack.push(3);
        stack.push(2);
        stack.push(4);
        stack.push(1);
        assertEquals(1, stack.findMin());
        assertEquals(1, stack.pop());
        assertEquals(2, stack.findMin());
        assertEquals(4, stack.pop());
        assertEquals(2, stack.findMin());
        assertEquals(2, stack.pop());


        assertEquals(3, stack.findMin());  // [3, 5]


        stack.push(7);   // [7,3,5]
        assertEquals(3, stack.findMin());
        stack.push(-1);  // [-1,7,3,5]
        assertEquals(-1, stack.findMin());

        assertEquals(-1, stack.pop());
        assertEquals(3, stack.findMin());
        assertEquals(7, stack.pop());
        assertEquals(3, stack.findMin()); // [3,5]
        stack.push(3);  // [3,3,5]
        assertEquals(3, stack.pop()); // [3,5]
        assertEquals(3, stack.findMin());
        assertEquals(3, stack.pop());  // [5]
        assertEquals(5, stack.findMin());
        assertEquals(5, stack.pop());  // []
        
        //栈为空，抛出异常
        expectedEx.expect(Exception.class);
        stack.pop();

    }
}