软件测试第一次作业：ERROR！！

Error: In the homework of computer graphics, an object does not follow my path to run.

Reason: ">" should be changed to ">=" in a judgment condition.

How to find it: First check whether the track is correct, and second output the variable that control the movement in the loop, then I notice that the values of the variable is wrong, finally I analyze the values and found this error.