完成多项式的运算，可以输入完整的多项式，包含括号，加减乘除求余等-complete polynomial arithmetic, can be imported complete polynomial, includes brackets for the arithmetic, etc. I

实现计算器加减乘除，乘方开方等基本运算，还能用键盘来操作-Addition and subtraction multiplication and division to achieve calculator, involution prescribing the basic operations, but also to use the keyboard to operate

计算器，实现加减乘除、函数、求π等基本运算。-Calculator, to achieve the function for PI, add, subtract, multiply and divide, and other basic operations.