用两个指针就好了~
import java.util.Scanner;
public class test6 {
public static void main(String[] args) {
Scanner s = new Scanner(System.in);
String str = s.nextLine();
String q = "";
boolean flag = true;
for(int i = 0, j = str.length() -1; i <= j;){//双指针
if(str.charAt(i) == str.charAt(j)){
i ++;
j --;
}
else{
flag = false;
break;
}
}
if(flag) System.out.println("yes");
else System.out.println("no");
}
}