Disheartened

Deleted User wrote: »

You've skipped a lot of the complications. You can't just sort the array.

Am I the only one who has actually finished this? I was expecting more solutions.

rw999 wrote: »

...

TDD is great for these. Try to think of the edge cases, and add a test. The test can be simple, just print to stdout and validate it in your head, particularly if pressed for time. When you write a little code, run the solution to see if it has worked as you intended.

Get something working. Think about how it could be done in O(n) time/memory or be adapted to handle variations of the question, but get a naive solution working before worrying too much about these things. I often find you see obvious ways for improvement from working out the naive case and you will at least have something to show. This is particularly relevant when applying for a grad role as the interviewer does not necessarily expect the ideal solution.

beauf wrote: »

Is there no library that has a isDate/isTime function to check valid time formats.
Modify the string so its this format and pass it into such a function.
I assume you can't do this as you don't have access to such libraries.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DateValidator
{
    public class DateValidator
    {
        private const int highestMinuteOrSecondOneValue = 5;
        private const int highestMinuteOrSecondTwoValue = 9;

        public int GetLatestMinuteOrSecond(DateResult result)
        {
            result.Numbers = result.Numbers.OrderByDescending(x => x).ToList();
            int latestSecondMinute = result.Numbers[0];
            result.Numbers.Remove(latestSecondMinute);
            int? latestFirstMinute = null;
            foreach(int testValue in result.Numbers)
            {
                if (testValue <= highestMinuteOrSecondOneValue)
                {
                    latestFirstMinute = testValue;
                    break;
                }
            }
            if (latestFirstMinute == null) { latestFirstMinute = highestMinuteOrSecondOneValue + 1; }
            result.Numbers.Remove((int)latestFirstMinute);
            return (int)latestFirstMinute * 10 + latestSecondMinute;
        }

        public int GetLatestHour(DateResult result)
        {
            result.Numbers = result.Numbers.OrderByDescending(x => x).ToList();
            int latestSecondHour = result.Numbers[0];
            result.Numbers.Remove(latestSecondHour);
            int latestFirstHour = result.Numbers[0];
            return latestFirstHour * 10 + latestSecondHour;
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DateValidator
{
    public class DateResult
    {
        public List<int> Numbers = new List<int>();

        public const int MaxHour = 23;
        public const int MaxMinute = 59;
        public const int MaxSecond = 59;

        public bool ValidHour;
        public bool ValidMinute;
        public bool ValidSecond;

        public int Hour;
        public int Minute;
        public int Second;

        public string Message;

        public void GetMessage()
        {
            if (Hour > MaxHour)
                Message = "Cannot get valid hour.";
            else if (Minute > DateResult.MaxMinute)
                Message = "Cannot get valid minute.";
            else if (Second > DateResult.MaxSecond)
                Message = "Cannot get valid second.";
            else
                Message = new DateTime(1, 1, 1, Hour, Minute, Second).ToLongTimeString();
        }
    }
}

using DateValidator;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DateValidatorConsole
{
    class Program
    {
        static void Main(string[] args)
        {
            List<DateResult> results = new List<DateResult>();
            results.Add(GetResult(new List<int>() { 0, 0, 0, 7, 8, 9 }));
            results.Add(GetResult(new List<int>() { 2, 4, 5, 9, 5, 9 }));
            results.Add(GetResult(new List<int>() { 0, 0, 0, 0, 0, 1 }));
            results.Add(GetResult(new List<int>() { 2, 3, 5, 9, 5, 9 }));
            results.Add(GetResult(new List<int>() { 0, 0, 2, 2, 5, 6 }));
            results.Add(GetResult(new List<int>() { 0, 0, 5, 9, 5, 9 }));
            results.Add(GetResult(new List<int>() { 1, 8, 3, 2, 6, 4 }));
            results.Add(GetResult(new List<int>() { 8, 4, 7, 1, 8, 6 }));
            results.Add(GetResult(new List<int>() { 8, 9, 0, 4, 0, 0 }));
            foreach (DateResult result in results)
            {
                Console.WriteLine(result.Message);
            }
            Console.Read();
        }

        static private DateResult GetResult(List<int> numbers)
        {
            DateValidator.DateValidator validator = new DateValidator.DateValidator();
            DateResult result = new DateResult { Numbers = numbers };
            result.Second = validator.GetLatestMinuteOrSecond(result);
            result.Minute = validator.GetLatestMinuteOrSecond(result);
            result.Hour = validator.GetLatestHour(result);
            result.GetMessage();
            return result;
        }
    }
}

smacl wrote: »

A breadth first traversal (BFT) modified to terminate when any visited vertex was 10 minutes from the root vertex would do the trick. Initial seed point selection is trickier, but bearing in mind you need to visit the map edges, I'd start by placing a seed point at edge, carry out a BFT, take the two edge points and repeat with those. Given two edge points, carry out a BFT search on each, looking for a common vertex found by both seed points. That is one position we need a fire station. Remove all points visited by a BFT from that fire station and repeat until all points are exhausted.

Maybe you guys are faster coders, but I'd be chuffed to get this done in a morning. No way is that a 40 minute exercise for this ageing code monkey.

14ned wrote: »

Anyway keeping fresh on interviewing no longer matters to me anymore. This morning the contract came through for me leaving contracting, I am returning to permanent to ride out the coming tech bubble collapse. 100% remote for a US finance firm, paid at US wages which is double the max you'd ever get paid here, all routed through my Irish limited company to mitigate taxes, and with Irish public holidays and vacation time which is double what they offered initially. I am very pleased indeed to have landed this role, but I am sad to leave contracting. I really love contracting, I will miss it sorely.

14ned wrote: »

Anyway keeping fresh on interviewing no longer matters to me anymore. This morning the contract came through for me leaving contracting, I am returning to permanent to ride out the coming tech bubble collapse. 100% remote for a US finance firm, paid at US wages which is double the max you'd ever get paid here, all routed through my Irish limited company to mitigate taxes, and with Irish public holidays and vacation time which is double what they offered initially. I am very pleased indeed to have landed this role, but I am sad to leave contracting. I really love contracting, I will miss it sorely.

Niall

14ned wrote: »

It's about six lines of C or Python code to implement. Both have standard library functions which do all the work. So I'd say a very rudimentary problem to solve.

function earliest(time_digits) {
    const in_range = (a, b, limit=60) => 0 <= (a * 10 + b) < limit
    const time_str = (h1, h2, m1, m2, s1, s2) => (in_range(h1, h2, 24) && in_range(m1, m2) && in_range(s1, s2)) ? `${h1}${h2}:${m1}${m2}:${s1}${s2}` : null
    const [a, b, c, d, e, f] = time_digits.sort()
    return (time_str(a, b, c, d, e, f) || time_str(a, b, c, e, d, f) || time_str(a, d, b, e, c, f) || time_str(a, b, c, e, d, f))
}

earliest([5, 4, 3, 2, 1, 0])
"01:23:45"