imported>Unknown at 05:23, 7 February 2021

2021-02-07T05:23:29Z

New page

= 실행코드 =
import javax.swing.JOptionPane;
public class BaseBall {
private int correctNumber;
public static void main(String[] args) {
BaseBall oneGame = new BaseBall();
oneGame.setCorrectNumber();
int guess = 0, result = 0;
do
{
guess = oneGame.inputGuess();
result = oneGame.compare(guess);
if (result != 30)
JOptionPane.showMessageDialog(null, (result / 10) + " Strike, "
+ (result % 10) + " Ball");
}while (result != 30);
oneGame.displayResult();
}
public void setCorrectNumber()
{
int setNumber = 0;
do
{
setNumber = (int) (Math.random() * 10);
}while (setNumber == 0);
correctNumber = setNumber;
do
{
setNumber = (int) (Math.random() * 10);
}while (correctNumber == setNumber);
correctNumber = correctNumber * 10 + setNumber;
do
{
setNumber = (int) (Math.random() * 10);
}while (((int)(correctNumber / 10)) == setNumber
|| ((int)(correctNumber % 10)) == setNumber);
correctNumber = correctNumber * 10 + setNumber;
}
public int inputGuess()
{
String input = JOptionPane.showInputDialog("Enter three different number\n");
int guess = Integer.parseInt(input);
return guess;
}
public int compare(int aGuess)
{
int compareResult = 0, cCorrect = correctNumber;
int firstGuess = (int) (aGuess / 100);
int secondGuess = ((int) (aGuess / 10)) % 10;
int thirdGuess = aGuess % 10;
if (((int)(cCorrect / 100) == firstGuess))
compareResult ++;
cCorrect = cCorrect % 100;
if (((int)(cCorrect / 10) == secondGuess))
compareResult ++;
cCorrect = cCorrect % 10;
if (cCorrect == thirdGuess)
compareResult ++;
compareResult *= 10;
cCorrect = correctNumber;
if (((int)(cCorrect / 100)) == secondGuess
|| ((int)(cCorrect / (100))) == thirdGuess)
compareResult ++;
cCorrect = cCorrect % 100;
if (((int)(cCorrect / 10)) == firstGuess
|| ((int)(cCorrect / (10))) == thirdGuess)
compareResult ++;
cCorrect = cCorrect % 10;
if ((cCorrect == firstGuess) || (cCorrect == secondGuess))
compareResult ++;
return compareResult;
}
public void displayResult()
{
JOptionPane.showMessageDialog(null, "You are right!\n Answer is " + correctNumber);
}
}
= 잡담 =
* 정답을 int변수 3자리 숫자로 표현해서 만들어봤더니 코드만 더 길어졌네요 -0-;; - [[문원명]]

= 개선 시도 =
집에서 놀다가 우연히 여기를 와서 고쳐봅니다. 조금 더 생각해 보시면 되지요. 저에게 재미있는 경험을 주었는데, 문원명 후배님도 보시라고 과정을 만들어 두었습니다. 선행학습으로 JUnit이 있어야 하는데, http://junit.org 에서 궁금하시면 [http://www.devx.com/Java/Article/31983/0/page/2 관련문서]를 보시고 선배들에게 물어보세요.

용기가 내셔서 저를 찾으면... ;;
--NeoCoin
* 처음에는 Test-Driven Development 에 입각하여 만들어 보려고 했으나, Java를 거의 처음 시작하고 프로그래밍 경험의 공백기간이 길었던게 큰 타격이었습니다ㅠㅠ. 결국에는 문법과 알고리즘에만 신경을 쓰다보니 TDD방식으로 다루기가 쉽지 않네요. 개선 조언을 해 주신 류상민 선배님 감사합니다 ㅎㅎ -[[문원명]]
** 오해가 있을 것 같아서 코멘트 합니다. TDD는 별로 중요하지 않습니다. 결정적으로 저는 '''TDD로 하지 않았습니다.''' 그냥 Refactoring시 Regression Test를 위해서 JUnit 을 썼을 뿐이에요.--NeoCoin
*** 네, 제가 TDD의 의미를 확실히 하지 못한 것 같습니다. TDD책의 앞부분만 읽어 보았는데, 계속해서 더 읽어야 나가야겠다는 다짐이 드네요. 관심 가져주셔서 고맙습니다 ㅋ -[[문원명]]
== 과정 ==
초기의 테스트 가능하도록 원하는 값으로 무작위로 나오는 답안을 세팅하는 함수 추가.
// ..생략
void setCorrectNumber(int in) {
correctNumber = in;
}

@Test
public void test2() {
BaseBall oneGame = new BaseBall();
oneGame.setCorrectNumber(123);
assertEquals(30, oneGame.compare(123));
assertEquals(10, oneGame.compare(100, 123));
assertEquals(2, oneGame.compare(310, 123));
}
//..생략

setCorrectNumber 하기도 귀찮아서 compare 부분을 확장 , 내부에서 쓰일일이 없는 함수로 제거 목적으로 코스 수정
@Test
public void test2() {
BaseBall oneGame = new BaseBall();
assertEquals(30, oneGame.compare(123, 123));
assertEquals(10, oneGame.compare(100, 123));
assertEquals(2, oneGame.compare(310, 123));
}

public int compare(int aGuess) {
return compare(aGuess, correctNumber);
}
public int compare(int aGuess, int answer) {
correctNumber = answer;

int compareResult = 0, cCorrect = correctNumber;
//생략
}

readability 를 위해 필요없는 typecasting 문법들 제거 (Java Language Specification의 규칙들을 보세요. 해당 typecasting은 거의다 필요 없는겁니다.) 유의미한 단위로 분리
public int compare(int aGuess, int answer) {
correctNumber = answer;

int compareResult = 0, cCorrect = correctNumber;
int firstGuess = aGuess / 100 % 10;
int secondGuess = aGuess / 10 % 10;
int thirdGuess = aGuess % 10;

if (cCorrect / 100 == firstGuess)
compareResult++;
cCorrect = cCorrect % 100;
if (cCorrect / 10 == secondGuess)
compareResult++;
cCorrect = cCorrect % 10;
if (cCorrect == thirdGuess)
compareResult++;
compareResult *= 10;

cCorrect = correctNumber;
if ((cCorrect / 100) == secondGuess || (cCorrect / 100) == thirdGuess)
compareResult++;
cCorrect = cCorrect % 100;
if ((cCorrect / 10) == firstGuess || (cCorrect / 10) == thirdGuess)
compareResult++;
cCorrect = cCorrect % 10;
if ((cCorrect == firstGuess) || (cCorrect == secondGuess))
compareResult++;
return compareResult;
}
특정 포지션의 숫자를 얻어오기 위한 반복 부분들 발견, 특정 포지션을 얻어오는 함수 만들기
int positionNum(int value, int pos) {
if (pos < 1)
throw new IndexOutOfBoundsException("pos값은 1이상을 넣어주세요.");
int a = value % (int) Math.pow(10, pos);
return a / (int) Math.pow(10, pos - 1);
}

@Test
public void getPositionNum() {
assertEquals(3, positionNum(123, 1));
assertEquals(2, positionNum(123, 2));
assertEquals(1, positionNum(123, 3));
}

해당 함수를 알고리즘에 적용, Test는 계속 녹색 .
결과 값을 의미를 드러낼수 있도록 변경
더이상 함수가 this.correctNumber에 의존할 필요 없으므로 코드 개선
public int compare(int aGuess, int cCorrect) {
int firstGuess = positionNum(aGuess,3);
int secondGuess = positionNum(aGuess,2);
int thirdGuess = positionNum(aGuess,1);

int strike=0;
if (positionNum(cCorrect,3) == firstGuess)
strike++;
if (positionNum(cCorrect,2) == secondGuess)
strike++;
if (positionNum(cCorrect,1) == thirdGuess)
strike++;

int ball=0;
if (positionNum(cCorrect,3) == secondGuess || positionNum(cCorrect,3) == thirdGuess)
ball++;
if (positionNum(cCorrect,2) == firstGuess || positionNum(cCorrect,2) == thirdGuess)
ball++;
if ((positionNum(cCorrect,1) == firstGuess) || (positionNum(cCorrect,1) == secondGuess))
ball++;
return ball + strike*10;
}
코드에 약간 패턴이 보인다. inline시키면 보일것 같다. 그래서 xxxGuess 를 inline
public int compare(int aGuess, int answer) {
int cCorrect = answer;
int strike=0;
if (positionNum(cCorrect,3) == positionNum(aGuess,3))
strike++;
if (positionNum(cCorrect,2) == positionNum(aGuess,2))
strike++;
if (positionNum(cCorrect,1) == positionNum(aGuess,1))
strike++;

int ball=0;
if (positionNum(cCorrect,3) == positionNum(aGuess,2) || positionNum(cCorrect,3) == positionNum(aGuess,1))
ball++;
if (positionNum(cCorrect,2) == positionNum(aGuess,3) || positionNum(cCorrect,2) == positionNum(aGuess,1))
ball++;
if ((positionNum(cCorrect,1) == positionNum(aGuess,3)) || (positionNum(cCorrect,1) == positionNum(aGuess,2)))
ball++;
return ball + strike*10;
}

숫자 패턴을 파악하고 중복 개선, magic number 제거
public int compare(int aGuess, int cCorrect) {
final int START_POS = 1,END_POS = 3;

int strike = 0;
for (int pos = END_POS; pos >=START_POS; pos--) {
if (positionNum(cCorrect, pos) == positionNum(aGuess, pos))
strike++;
}

int ball = 0;
for (int corPos = END_POS; corPos >=START_POS; corPos--) {
for (int guePos = END_POS; guePos > 0; guePos--) {
if (corPos != guePos && positionNum(cCorrect, corPos) == positionNum(aGuess,guePos))
ball++;
}
}
return ball + strike * 10;
}

두개의 루프의 정확한 의미 파악, 합침
public int compare(int aGuess, int cCorrect) {
final int START_POS = 1, END_POS = 3;

int strike = 0, ball = 0;

for (int corPos = END_POS; corPos >= START_POS; corPos--) {
for (int guePos = END_POS; guePos >= START_POS; guePos--) {
if (positionNum(cCorrect, corPos) == positionNum(aGuess, guePos)) {
if (corPos == guePos)
strike++;
else
ball++;
}
}
}
return ball + strike * 10;
}

해당 루틴이 지날때 마다 result 값에 10과 1을 더해주는 방식으로 바꿈
public int compare(int aGuess, int cCorrect) {
final int START_POS = 1, END_POS = 3, STRIKE_DELTA = 10, BALL_DELTA = 1;

int result = 0; //10자리가 strike, 1자리고 ball 값
for (int corPos = END_POS; corPos >= START_POS; corPos--)
for (int guePos = END_POS; guePos >= START_POS; guePos--)
if (positionNum(cCorrect, corPos) == positionNum(aGuess, guePos))
result += (corPos == guePos) ? STRIKE_DELTA : BALL_DELTA;
return result;
}

기타 overloading된 무의미한 compare를 정리. 소스상 setCorrectNumber를 생성자로 옮김.
더 개선하고 싶으나 그냥 하기 지쳐서 여기서 그만..
package test;

import static org.junit.Assert.assertEquals;
import org.junit.Test;
import javax.swing.JOptionPane;

public class BaseBall {
private int correctNumber;

public static void main(String[] args) {
final int END_GAME_NUM = 30;

BaseBall oneGame = new BaseBall();
while (true) {
int result = oneGame.runOneTurn();
if (result == END_GAME_NUM)
break;
else
JOptionPane.showMessageDialog(null,
String.format("%d Strike, %d Ball", result / 10, result % 10));
}
oneGame.displayResult();
}

public int runOneTurn() {
return compare(this.correctNumber, inputGuess());
}

public BaseBall() {
int setNumber = 0;
do {
setNumber = (int) (Math.random() * 10);
} while (setNumber == 0);
correctNumber = setNumber;
do {
setNumber = (int) (Math.random() * 10);
} while (correctNumber == setNumber);
correctNumber = correctNumber * 10 + setNumber;
do {
setNumber = (int) (Math.random() * 10);
} while (correctNumber / 10 == setNumber
|| correctNumber % 10 == setNumber);
correctNumber = correctNumber * 10 + setNumber;
}

public int inputGuess() {
String input = JOptionPane
.showInputDialog("Enter three different number\n");
int guess = Integer.parseInt(input);
return guess;
}

int positionNum(int value, int pos) {
if (pos < 1)
throw new IndexOutOfBoundsException("pos값은 1이상");
int a = value % (int) Math.pow(10, pos);
return a / (int) Math.pow(10, pos - 1);
}

public int compare(int aGuess, int cCorrect) {
final int START_POS = 1, END_POS = 3, STRIKE_DELTA = 10, BALL_DELTA = 1;

int result = 0; // 10자리가 strike, 1자리가 ball 값
for (int corPos = END_POS; corPos >= START_POS; corPos--)
for (int guePos = END_POS; guePos >= START_POS; guePos--)
if (positionNum(cCorrect, corPos) == positionNum(aGuess, guePos))
result += (corPos == guePos) ? STRIKE_DELTA : BALL_DELTA;
return result;
}

public void displayResult() {
JOptionPane.showMessageDialog(null, "You are right!\n Answer is "
+ correctNumber);
}

@Test
public void getPositionNum() {
assertEquals(3, positionNum(123, 1));
assertEquals(2, positionNum(123, 2));
assertEquals(1, positionNum(123, 3));
}

@Test
public void test2() {
BaseBall oneGame = new BaseBall();
assertEquals(30, oneGame.compare(123, 123));
assertEquals(10, oneGame.compare(100, 123));
assertEquals(2, oneGame.compare(310, 123));
}
}

JTDStudy/첫번째과제/원명 - Revision history

imported>Unknown at 05:23, 7 February 2021