Home/ Questions/Q 13785
Next
In Process

askthedev.com Latest Questions

Asked: 2024-09-26T23:53:09+05:30 In:

How to Calculate Manhattan Distances Between Keys on a QWERTY Keyboard Using Python?

I recently stumbled upon this fun idea of calculating distances between keys on a QWERTY keyboard, and it got me thinking—how would we go about solving this in a creative way?

Imagine you’re trying to type out a message, and you’re curious about how much finger travel is involved between different characters. Let’s say you have a simple QWERTY layout like the one we all know:

“`
q w e r t y u i o p
a s d f g h j k l
z x c v b n m
“`

I thought it’d be interesting to create a little problem related to this concept. What if we could define the distance between any two keys based on their physical positions on the keyboard? For simplicity, let’s consider the distance to be the Manhattan distance—meaning you can only move left/right or up/down and not diagonally.

So, here’s the challenge:

1. Write a function that takes two characters as input, say ‘f’ and ‘g’.
2. Calculate the Manhattan distance between them. Since ‘f’ is located at (3, 2) and ‘g’ is at (3, 3) on the keyboard grid, the distance would be 1.

But let’s take it a step further! What if we wanted to input a string, like “hello world”, and compute the total distance of moving from one character to the next?

And to make it even more interesting, let’s include some rules:
– Treat spaces as valid inputs but assign a distance of zero when moving to or from a space.
– If a character is not found on the QWERTY layout (let’s say numbers or symbols), just return an error message.

I’d love to see what different approaches you all come up with. Are you going to do it using basic loops, or are you going to get creative with data structures? And hey, feel free to share your code snippets and solutions! Can’t wait to see what you come up with!

Share

    Leave an answer

    You must login to add an answer.

    Need An Account,

    2 Answers

    1. To calculate the Manhattan distance between keys on a QWERTY keyboard, we can represent the keyboard layout as a 2D grid. Each key can be mapped to its coordinates, allowing easy distance calculations. Below is a simple Python function that computes the Manhattan distance between two keys, as well as a function that computes the total distance for a given input string, handling spaces and invalid characters accordingly.

      
keyboard_layout = {
    'q': (0, 0), 'w': (0, 1), 'e': (0, 2), 'r': (0, 3), 't': (0, 4),
    'y': (0, 5), 'u': (0, 6), 'i': (0, 7), 'o': (0, 8), 'p': (0, 9),
    'a': (1, 0), 's': (1, 1), 'd': (1, 2), 'f': (1, 3), 'g': (1, 4),
    'h': (1, 5), 'j': (1, 6), 'k': (1, 7), 'l': (1, 8),
    'z': (2, 0), 'x': (2, 1), 'c': (2, 2), 'v': (2, 3), 'b': (2, 4),
    'n': (2, 5), 'm': (2, 6), ' ': (3, 0)  # treating space as a valid key with zero distance
}

def manhattan_distance(key1, key2):
    if key1 not in keyboard_layout or key2 not in keyboard_layout:
        return "Error: One of the keys is not valid."
    pos1 = keyboard_layout[key1]
    pos2 = keyboard_layout[key2]
    return abs(pos1[0] - pos2[0]) + abs(pos1[1] - pos2[1])

def total_distance(input_string):
    distance = 0
    for i in range(len(input_string) - 1):
        if input_string[i] == ' ':
            continue
        distance += manhattan_distance(input_string[i], input_string[i + 1])
    return distance

# Example usage
print(total_distance("hello world"))  # Calculate total typing distance for "hello world"

    2. Calculate Manhattan Distance on QWERTY Keyboard

      Let’s solve the problem step by step! We need to create a function to calculate the Manhattan distance between two keys based on their positions on a QWERTY keyboard.

              
function getKeyPosition(key) {
    const keyboard = [
        ['q', 'w', 'e', 'r', 't', 'y', 'u', 'i', 'o', 'p'],
        ['a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l'],
        ['z', 'x', 'c', 'v', 'b', 'n', 'm']
    ];

    for (let i = 0; i < keyboard.length; i++) {
        const index = keyboard[i].indexOf(key);
        if (index !== -1) {
            return { x: index, y: i };
        }
    }
    return null; // Key not found
}

function manhattanDistance(key1, key2) {
    const pos1 = getKeyPosition(key1);
    const pos2 = getKeyPosition(key2);
    if (!pos1 || !pos2) {
        return "Error: Key not found!";
    }
    return Math.abs(pos1.x - pos2.x) + Math.abs(pos1.y - pos2.y);
}

function totalDistance(input) {
    let total = 0;
    for (let i = 0; i < input.length - 1; i++) {
        const currentChar = input[i];
        const nextChar = input[i + 1];
        
        // Check if the current character is a space
        if (currentChar === ' ' || nextChar === ' ') {
            continue; // No distance for spaces
        }

        const distance = manhattanDistance(currentChar, nextChar);
        if (typeof distance === 'string') {
            return distance; // Return error message
        }
        total += distance;
    }
    return total;
}

// Example usage:
const message = "hello world";
console.log("Total distance: ", totalDistance(message));

      This code defines functions to find the positions of keys, calculate the Manhattan distance, and compute the total distance for a string. It treats spaces as zero distance and handles errors for unsupported characters!

    Related Questions