[BOJ] 1213 팰린드롬 만들기 (JAVA)

https://www.acmicpc.net/problem/1213

1213번: 팰린드롬 만들기

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
	
    public static void main(String[] args) throws Exception {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        char[] input = br.readLine().toCharArray();
        int[] cnt = new int[91];
        int odd = 0;
        int len = 0;
        for (int i = 0; i < input.length; i++) {
            if (++cnt[input[i]] % 2 == 0) odd--;
            else odd++;
            len++;
        }

        if (1 < odd || (odd == 1 && len % 2 == 0)) {
            System.out.print("I'm Sorry Hansoo");
            return;
        }

        String one = "";
        StringBuilder sb = new StringBuilder();
        for (int i = 65; i <= 90; i++) {
            int num = cnt[i];

            if (num == 0) continue;

            for (int j = 0; j < num / 2; j++) {
                sb.append((char) i);
            }

            if (cnt[i] % 2 == 1) one += (char) i;
        }

        System.out.print(sb);
        System.out.print(one);
        System.out.print(sb.reverse());

    }
	
}