Question

A mobile phone has 12 keys for input, (‘1’, ‘2’, ‘3’, ‘4’, ‘5’, ‘6’, ‘7’, ‘8’, ‘9’, ‘0’, ‘*’ and ‘#’).

In standard text input mode each key can be used to input the letters of the alphabet and the space character. For example, to access the letter ‘b’ the user would press the ‘2’ key twice.

It takes a user a minimum of 100 ms to press a key. If a user has to use the same key to input consecutive characters there must be at least a 0.5 second pause for the phone to accept that the next key press represents a new character.

I want to write an console application which accepts any string that can be entered using the key assignments in the grid using C#. The application should accept input from a user and calculate the minimum time required for the user to input that string using the key pad and the sequence of keys that would be required.

If somebody know who can help me to write program.

Answer 1

This should give you an idea:

class Mobilegrid
{
    const int MIN_DURATION = 100;
    const int WAIT_DURATION = 500;

    private static Dictionary<Char, Tuple<Char, int>> Grid;
    static Mobilegrid()
    {
        Grid = new Dictionary<Char, Tuple<Char, int>>();
        Grid.Add('a', Tuple.Create('2', 1));
        Grid.Add('b', Tuple.Create('2', 2));
        Grid.Add('c', Tuple.Create('2', 3));
        Grid.Add('d', Tuple.Create('3', 1));
        Grid.Add('e', Tuple.Create('3', 2));
        Grid.Add('f', Tuple.Create('3', 3));
        Grid.Add('g', Tuple.Create('4', 1));
        Grid.Add('h', Tuple.Create('4', 2));
        Grid.Add('i', Tuple.Create('4', 3));
        Grid.Add('j', Tuple.Create('5', 1));
        Grid.Add('k', Tuple.Create('5', 2));
        Grid.Add('l', Tuple.Create('5', 3));
        Grid.Add('m', Tuple.Create('6', 1));
        Grid.Add('n', Tuple.Create('6', 2));
        Grid.Add('o', Tuple.Create('6', 3));
        Grid.Add('p', Tuple.Create('7', 1));
        Grid.Add('q', Tuple.Create('7', 2));
        Grid.Add('r', Tuple.Create('7', 3));
        Grid.Add('s', Tuple.Create('7', 4));
        Grid.Add('t', Tuple.Create('8', 1));
        Grid.Add('u', Tuple.Create('8', 2));
        Grid.Add('v', Tuple.Create('8', 3));
        Grid.Add('w', Tuple.Create('9', 1));
        Grid.Add('x', Tuple.Create('9', 2));
        Grid.Add('y', Tuple.Create('9', 3));
        Grid.Add('z', Tuple.Create('9', 4));
    }

    public static int CalculateMinimumTime(String word)
    {
        int totalMillis = 0;
        for (int index = 0; index < word.Length; index++)
        {
            Tuple<Char, int> charInfo = Grid[word[index]];
            int Pos = charInfo.Item2;
            int clickTime = Pos * MIN_DURATION;
            if (index != 0)
            {
                Tuple<Char, int> lastCharInfo = Grid[word[index - 1]];
                if (lastCharInfo.Item1 == charInfo.Item1)
                    clickTime += WAIT_DURATION;
            }
            totalMillis += clickTime;
        }
        return totalMillis;
    }
}

Then you’d get the total minimum required time:

int totalMillis = Mobilegrid.CalculateMinimumTime("hello"); //1800

Note: you have to add special chars like white-space.