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  1. Prepare
  2. Algorithms
  3. Implementation
  4. Beautiful Days at the Movies
  5. Discussions

Beautiful Days at the Movies

  • TuanBao
     + 0 comments

    This is my Java 8 solution, feel free to ask me any questions.

    First solution:

    public static int beautifulDays(int i, int j, int k) {
    int days = 0;
    while(i <= j) {
        //calculate reversed day
        String reverseDayStr = new StringBuilder(i + "")
            .reverse()
            .toString();
        int reverseDay =Integer.valueOf(reverseDayStr); 
        
        if( reverseDay == i || 
            Math.abs(reverseDay - i) % k == 0) days++;
        i++;
    }
    return days;
}

    Second solution:

    public static int beautifulDays(int i, int j, int k) {
    int days = 0;
    while(i <= j) {
        //calculate reversed day
        int currentDay = i;
        int reverseDay = 0;
        while(currentDay > 0) {
            int digit = currentDay % 10;
            currentDay = currentDay / 10;
            reverseDay = reverseDay * 10 + digit;
        } 
        
        if( reverseDay == i || 
            Math.abs(reverseDay - i) % k == 0) days++;
        i++;
    }
    return days;
}