1、输入一个百分制成绩，要求输出成绩等级A,B,C,D,E。其中90分~100分为A，80分~89分为B，70分~79分为C，60分~69分为D，60分以下为E。 要求：

（1）分别用if语句和switch语句实现。

（2）输入百分制成绩后要判断该成绩的合理性，对不合理的成绩应输出出错信息。

编写求解程序，存为m脚本文件。

-1. Enter a percentile score, the required output grades A, B, C, D, E. 90 minutes to 100 minutes A, 80 points to 89 into B, 70 minutes to 79 are divided into C, 60 minutes to 69 are divided into D, 60 points or less E. Claim:

(1) were achieved with an if statement and the switch statement.

(2) Enter the percentile score after going to judge the reasonableness of the achievements of unreasonable results should output an error message.

 　Write solver, saved as m scr ipt file.