FastScanner.java

class FastScanner {
    private final int radix = 10;
    private int pos;
    private String line;

    void init(String line) {
        this.line = line;
        pos = 0;
    }

    boolean hasNext() {
        return pos < line.length();
    }

    char nextChar() {
        char result = 0;
        if (hasNext()) {
            result = line.charAt(pos++);
        }
        if (hasNext()) {
            ++pos;
        }
        return result;
    }

    long nextLong() {
        int begin = pos;
        long result = 0;
        boolean negative = false;
        for (char c; hasNext() && (c = line.charAt(pos)) != ' '; ++pos) {
            if (c == '-') negative = true;
            if (c == '+' || c == '-' || c == '.') continue;
            result *= radix;
            int digit = Character.digit(c, radix);
            if (digit == -1) {
                throw new NumberFormatException("'" + line.substring(begin, pos + 1) + "' in '" + line + "'");
            }
            result += digit;
        }
        ++pos;
        return negative ? -result : result;
    }

    int nextInt() {
        return (int) nextLong();
    }

    UUID nextUUID() {
        return UUID.fromString(next());
    }

    String next() {
        int begin = pos, end = pos;
        while (hasNext() && line.charAt(pos) != ' ') {
            ++pos;
            ++end;
        }
        String result = line.substring(begin, end);
        ++pos;
        return result;
    }
}