Java를 이용해 int배열로 Stack 구현해보기

Stack.java

package javaStudy.Stack;

public interface Stack {
    boolean push(int data);
    int pop();
}

UseIntArrayStack.java

package javaStudy.Stack;

public class UseIntArrayStack implements Stack{
    private int[] stack;
    private int top;

    public UseIntStack(int size){
        this.stack = new int[size];
        this.top = -1;
    }

    public int getData(int idx){
        return this.stack[idx];
    }
    @Override
    public boolean push(int data) {
        if(top == stack.length-1){
            return false;
        }
        stack[++top] = data;
        return true;
    }

    @Override
    public int pop() {
        if(top == -1 ){
            System.out.println("Stack이 비었습니다.");
            return -1;
        }
        return stack[top--];
    }
}

useIntArrayStackTest.java

package test.Stack;

import javaStudy.Stack.UseIntStack;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.*;

class useIntArrayTest {
    UseIntArrayStack useIntStack;

    @BeforeEach
    void init(){
        useIntStack = new UseIntStack(10);
    }

    @Test
    void pushTest(){
        boolean result = true;
        for(int i=0; i < 10; i++){
            result = useIntStack.push(i);
        }

        for(int i=0; i < 10; i++){
            Assertions.assertEquals(i,useIntStack.getData(i));
        }
        Assertions.assertTrue(result);

    }
    @Test
    void pushExceptionTest(){
        boolean result = true;
        for(int i=0; i < 12; i++){
            result = useIntStack.push(i);
        }
        Assertions.assertFalse(result);
    }

    @Test
    void removeEmptyTest(){
        int result = useIntStack.pop();

        Assertions.assertEquals(-1,result);
    }
    @Test
    void removeTest(){
        for(int i=0; i < 10; i++){
            useIntStack.push(i);
        }
        int result = useIntStack.pop();
        Assertions.assertEquals(9,result);
    }

}