例子很簡單，設計一個程序，輸入三個整數，判斷這三個整數作為三邊的長度能否構成一個三角形，如果可以則返回三角形的類型（普通三角形，等腰三角形或者等邊三角形）
實現代碼（我自己隨便寫的做個例子用，估計代碼質量很差。。）：
public class JudgeTriangle
{
//普通三角形
private static int NORMAL_TRIANGLE = 0;
//等腰三角形
private static int ISOSCELES_TRIANGLE = 1;
//等邊三角形
private static int EQUILATERAL_TRIANGEL = 2;
//無法構成三角形
private static int ERROR_CODE = -1;
public int getNormalTriangle()
{
return NORMAL_TRIANGLE;
}
public int getIsoscelesTriangle()
{
return ISOSCELES_TRIANGLE;
}
public int getEquilateralTriangle()
{
return EQUILATERAL_TRIANGEL;
}
public int getErrorCode()
{
return ERROR_CODE;
}
public int judgeType(int a，int b，int c)
{
if ((a<=0)||(b<=0)||(c<=0))
{
return ERROR_CODE;
}
if ((a+b<c || Math.abs(a-b)>c) || (b+c<a || Math.abs(b-c)>a) || (a+c<b || Math.abs(a-c)>b))
{
return ERROR_CODE;
}
if (a==b || b==c || c==a)
{
if (a==b && b==c)
{
return EQUILATERAL_TRIANGEL;
}
else
{
return ISOSCELES_TRIANGLE;
}
}
else
{
return NORMAL_TRIANGLE;
}
}
}
單元測試代碼:
import static org.junit.Assert.*;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
public class JudgeTriangleTest {
private static JudgeTriangle judgeTriangle = new JudgeTriangle();
@Before
public void setUp() throws Exception {
}
@Test
public void testIsNormalTriangle() throws Exception {
assertEquals(judgeTriangle.getNormalTriangle()，judgeTriangle.judgeType(3， 4， 5));
}
@Test
public void testIsIsoscelesTriangle() throws Exception {
assertEquals(judgeTriangle.getIsoscelesTriangle()，judgeTriangle.judgeType(2， 2， 3));
}
@Test
public void testEquilateralTriangle() throws Exception {
assertEquals(judgeTriangle.getEquilateralTriangle()，judgeTriangle.judgeType(2， 2， 2));
}
@Test
public void testNotTriangle() throws Exception {
assertEquals(judgeTriangle.getErrorCode()，judgeTriangle.judgeType(10， -10， 10));
assertEquals(judgeTriangle.getErrorCode()，judgeTriangle.judgeType(10， 2， 2));
}
@After
public void tearDown() throws Exception {
}
}
