Atcoder Regular Contest #003

A - GPA計算

問題：http://arc003.contest.atcoder.jp/tasks/arc003_1#

import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner s = new Scanner(System.in);
    int n = s.nextInt();
    char[] cs = s.next().toCharArray();
    Arrays.sort(cs);
    double a = 0;
    List<Character> list = Arrays.asList('F', 'D', 'C', 'B', 'A');
    for (char c : cs) {
      a += list.indexOf(c);
    }
    System.out.println(a / n);
  }
}

B - さかさま辞書

問題：http://arc003.contest.atcoder.jp/tasks/arc003_2#

import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner s = new Scanner(System.in);
    int n = s.nextInt();
    List<String> list = new ArrayList<String>();
    for (int i = 0; i < n; ++i) {
      list.add(new StringBuilder(s.next()).reverse().toString());
    }
    Collections.sort(list);
    for (String line : list) {
      System.out.println(new StringBuilder(line).reverse().toString());
    }
  }
}