

实现代码:
java
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String s = sc.next();
int n = s.length();
int ans = 0;
for (int i = 0; i < n / 2; i++) {
char left = s.charAt(i);
char right = s.charAt(n - 1 - i);
int diff = Math.abs(left - right);
ans += Math.min(diff, 26 - diff);
}
System.out.println(ans);
sc.close();
}