

实现代码:
java
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
String s = scanner.next();
int n = s.length();
int m = n / 2;
int[] count1 = new int[26]; // 前半部分
int[] count2 = new int[26]; // 后半部分
for (int i = 0; i < m; i++) {
count1[s.charAt(i) - 'a']++;
}
for (int i = m; i < n; i++) {
count2[s.charAt(i) - 'a']++;
}
int maxSame = 0;
for (int a = 0; a < 26; a++) {
for (int b = 0; b < 26; b++) {
maxSame = Math.max(maxSame, count1[a] + count2[b]);
}
}
System.out.println(n - maxSame);
}