实现回文字符串判断 -- JAVA 算法学习

大一的时候老师上课的经典例子就是回文字符串判断，我觉得经典，也保留了下来。

很简单的判断，即字符串从前往后输出和从后往前输出都是一样的结果。是不是想到了什么，没错，就是栈(FIFO)，用这个就可以很好的解决这个问题啦~

publicclassHuiWenString {

      publicString isHuiWen(Stringstring){

            intmid;

            inttop=0;

            char[]charOne;

            if(string.length()==1)

                  return"Yes";

                  mid=string.length()/2;

            charOne=newchar[mid];

            //System.out.println("mid="+mid);

            for(inti= 0;i<mid;i++){

                  charOne[i]=string.charAt(i);

                  top++;

            }

            top--;

                  //charOne[top] = string.charAt(top);

                  //charOne[i-1] = string.charAt(i-1);

           //System.out.println("top="+top);

           // for(inti=0;i<charOne.length;i++)

            //System.out.println("char="+charOne[i]);

            if(string.length()%2==0){

                  System.out.println("s-mid="+string.charAt(mid)+"c-top="+charOne[top]);

                  System.out.println(string.charAt(mid)!=charOne[top]);

                  if(string.charAt(mid)!=charOne[top]){

                        return"NO1";

                  }else{      

                        top--;

                  for(intj=mid+1;j<string.length()-1;j++)

                        if(string.charAt(j)!=charOne[top--])

                              return"NO2";

                  }

                  return"YES";

            }else

                  for(intk=mid+1;k<string.length()-1;k++)

                        if(string.charAt(k)!=charOne[top--])

                        return"NO3";

            if(top==0)

            return"YES";

            return"Error";

      }

      publicstaticvoidmain(String[]args) {

            Scannerscanner=newScanner(System.in);

            System.out.println("请输入待判断的字符串：");

            Stringstring=scanner.nextLine();

            HuiWenStringhuiWenString=newHuiWenString();

            System.out.println(huiWenString.isHuiWen(string));

            

      }

}