说明: 此计算机可以计算同时超过多个操作项的什. 例如: y = 3 + 64 * (2 + 3^5) + sinPI 的值， 用括号区分优先级，如果有大量很长的算式需要计算，可以试一下这个计算器. 开发语言: C#语言,用Stack原理实现 -Note : This computer also can be calculated over a number of operational items even. For example : y = 3 64* (2 ^ 5) sinPI value, use brackets to distinguish between priority levels, if we have a lot of very long formula needs to be calculated to try the calculators. Language development : C# language, Stack principle used to achieve