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public static String getDecimal(long a, long b) {
    java.util.Vector<Long> nums = new java.util.Vector<Long>();
    StringBuffer res = new StringBuffer("0.");
    while (true) {
        nums.add(a);
        a *= 10;
        res.append(a/b);
        a %= b;
        if (a == 0) {
            return res.toString();
        }
        if (nums.contains(a)) {
            int off = nums.indexOf(a) + 2;
            return res.substring(0,off) + "{" + res.substring(off) + "}";
        }
    }
}