实现一个重言式的判别程序。逻辑表达式从键盘输入，长度不超过一行；逻辑运算符包括“|”、“&”、“~”，分别表示或、与、非，运算优先程度递增，括号内的运算优先。-To achieve a tautology of the discriminant procedure. Logical expression from the keyboard input, the length of no more than a line　logical operators, including " |" ," & " ," ~" , or, respectively, and, Africa, and computing priority increment operations in brackets first.