判断回文

package lanqiaobei;import java.util.*;public class Main {    static Scanner in =new Scanner(System.in);    static final int N=1000;    static int k;public static void main(String[] args) {while(in.hasNext()){String s=in.next();  Stack<Character> st=new Stack<Character>();  st.clear();  int l=s.length();  int mid=0;  if(l%2==0)     mid=l/2;  else mid=l/2+1;      for (int i = 0; i <l/2; i++){ st.push(s.charAt(i));  }      for (int i = mid; i < l; i++) {if(s.charAt(i)!=st.peek()) break;st.pop();   }      if(st.isEmpty())     System.out.println("Yes");      else     System.out.println("No");  }    }}

利用栈来判断回文简单，注意奇偶的处理即可