public class Mask {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println(getMask("12341234abcdefgfedbca22"));
}
public static boolean isMask(String str){
char[] a=str.toCharArray();
boolean tag=true;
for(int k=0;k<a.length/2;k++){
if(a[k]!=a[a.length-k-1]){
tag=false;
break;
}
}
return tag;
}
public static String getMask(String str){
char[] a=str.toCharArray();
for(int i=a.length;i>1;i--){
for(int s=0;s<=a.length-i;s++){
String res=str.substring(s, s+i);
if(isMask(res)){
return res;
}
}
}
return null;
}
}
结果是:defgfed