回文算法

package com.sjtu.design.excise;

import java.util.List;

import java.util.ArrayList;

import java.util.Scanner;

/**

 * @class 回文类

 * @author TangShuGuang

 */

public class Palindrome {

private Object stackElem[];

private int top;

private static Scanner input;

// 初始化栈

public Palindrome() {

stackElem = new Object[100];

top = 0;

}

public int length() {

return this.top;

}

// 入栈

public void push(Object stack) {

if (top == stackElem.length) {

// throw new Exception("栈已满!");

System.out.println("栈已满!");

} else {

stackElem[top++] = stack;

System.out.println("入栈" + stack);

}

}

// 出栈

public Object pop() {

if (top == 0) {

// throw new Exception("栈为空!");

System.out.println("栈为空!");

return null;

} else {

return stackElem[--top];// 删除然后返回现在的栈顶

}

}

/**

* 判断输入字符串是否为回文

* 

* @param word

*            输入待判定的字符串

*//*

* public void isPalindrome2(String word) { int len = word.length(); int mid =

* len / 2; String rword = "";

* 

* for (int i = 0; i < mid; i++) { this.push(i); } while (this.length() > 0) {

* rword += this.pop(); } if (word == rword) { System.out.println("Right！"); }

* else { System.out.println("Wrong!"); } }

*/

/**

* 判断输入字符串是否为回文

* 

* @param pValue

*            输入待判定的字符串

*/

public void isPalindrome(String pValue) { // 堆栈一

List<Character> stack = new ArrayList<Character>(); // 堆栈二

List<Character> stack2 = new ArrayList<Character>(); // 字符串长度的一半

int haflen = pValue.length() / 2;

for (int i = 0; i < haflen; i++) { // 字符进栈

stack.add(pValue.charAt(i)); // 倒序进栈

stack2.add(pValue.charAt(pValue.length() - i - 1));

} // 标识符

boolean bFlag = true; // 出栈并比较

for (int i = haflen - 1; i >= 0; i--) {

if (stack.remove(i) != stack2.remove(i)) {

bFlag = false;

break;

}

} // 返回比对结果

if (bFlag) {

System.out.println("Right！");

} else {

System.out.println("Wrong!");

}

}

public static void main(String[] args) {

Palindrome p = new Palindrome();

//input = new Scanner(System.in);

//String word = input.next();

String testData[] = { "123456", "abba", "cba", "12AB21" };

for (int i = 0; i < testData.length; i++) {

System.out.println("请输入字符:" + testData[i]);

p.isPalindrome(testData[i]);

}

}

}