299. Bulls and Cows

    /*
     * 299. Bulls and Cows
     * 2016-7-2 by Mingyang
     * 代码很丑，可是这个题目过于简单，不详谈
     * 特殊case  1122-》1222
     * guess里面的第一个2出现的时候会让我在cow上加1
     * 所以我先遍历的相等的这样就不会错了，不过代码可以修改的优化的地方很多，有时间慢慢写
     */
    public static String getHint(String secret, String guess) {
        int bull = 0;
        int cow = 0;
        HashSet<Character> set = new HashSet<Character>();
        int[] array = new int[10];
        for (int i = 0; i < secret.length(); i++) {
            char a = secret.charAt(i);
            array[a - '0']++;
            set.add(a);
        }
        for (int i = 0; i < guess.length(); i++) {
            char b = guess.charAt(i);
            if (guess.charAt(i) == secret.charAt(i)) {
                bull++;
                array[b - '0']--;
                continue;
            }
        }
        for (int i = 0; i < guess.length(); i++) {
            char b = guess.charAt(i);
            if (set.contains(b) && guess.charAt(i) != secret.charAt(i)) {
                if (array[b - '0'] > 0) {
                    cow++;
                    array[b - '0']--;
                }
            }
        }
        String res = bull + "A" + cow + "B";
        return res;
    }