1.画出流程图：
2.当n=4时，t2会越界而t1不会
3.当n=1的时候，会直接跳过while循环体
4.
点覆盖：{1,2,3,4,5,6,7,8,9,10,11}
边覆盖：{(1,2), (2,3), (2,9), (3,4), (4,7), (4,5), (5,6), (5,4), (6,4), (7,8), (7,9), (8,9), (9,10), (10, 11), (11,10), (10, end)}
主路径覆盖：
{(1,2,9,10,e), (1,2,3,4,7,9,10,e), (1,2,3,4,7,8,9,10,end),
(4,5,4), (4,5,6,4),
(5,4,5), (5,4,7,9,10,end), (5,4,7,8,9,10,end), (5,6,4,7,9,10,end), (5,6,4,7,8,9,10,end), (5,6,4,5),
(6,4,5,6), (6,4,7,9,10,end), (6,4,7,8,9,10,end),
(10,11,10), (11, 10, 11), (11,10,end)}
二、基于Junit及Eclemma（jacoco）实现一个主路径覆盖的测试。
测试代码：
结果：
