数据结构练习。。。。判断输入字符串是否为对称的-Data structure practice. . . . Enter the string to determine whether the symmetrical

随机输入一个数，判断它是不是对称数（回文数）（如3，121，12321，45254）。不能用字符串库函数-Enter a random number to determine the number it is not symmetrical (palindromic) (as 3,121,12321,45254).Can not use the string library functions

该段代码实现密码截取。对像ABBA，ABA，A,123321这样对称的码串变成12ABBA,ABAKK,51233214之后，找出输入码串中最长的有效码串。如输入 ABBA，输出长度4；输入abaaab，输出长度5(baaab的长度)-This code implements password interception.To like ABBA, ABA, A, 123321 such symmetrical code string into 12ABBA, ABAKK, 512