例子很简单，设计一个程序，输入三个整数，判断这三个整数作为三边的长度能否构成一个三角形，如果可以则返回三角形的类型（普通三角形，等腰三角形或者等边三角形）
实现代码（我自己随便写的做个例子用，估计代码质量很差。。）：
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; //等边三角形 private static int EQUILATERAL_TRIANGEL = 2; //无法构成三角形 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; } } } |
单元测试代码:
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 { } } |
