UTPC2011 B "(iwi)"

問題：http://atcoder.jp/problem/detail/26

コード

import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		char[] cs = s.next().toCharArray();
		int sum = 0;
		int n = cs.length;
		for (int i = 0; i < n / 2; ++i) {
			int j = n - i - 1;
			if (cs[i] == 'w' || cs[i] == 'i' || cs[j] == 'w' || cs[j] == 'i') {
				if (cs[i] != cs[j]) {
					++sum;
				}
			} else {
				if (!(cs[i] == '(' && cs[j] == ')')
						&& !(cs[i] == ')' && cs[j] == '(')) {
					++sum;
				}
			}
		}
		if (n % 2 > 0) {
			if (cs[n / 2] != 'w' && cs[n / 2] != 'i') {
				++sum;
			}
		}
		System.out.println(sum);
	}
}