Daily Challenge #6 - Grandma and her friends

def getDistance(visitOrder, friendTownList)
  townHash = Hash[*friendTownList]
  visitOrder.each {|f| raise "IDK where #{f} lives!" if !townHash.key? f }
  [0, *visitOrder.map(&proc {|f| townHash[f][1 .. -1].to_i }), 0]
    .each_cons(2)
    .map(&proc {|a, b| (a - b).abs })
    .sum
end

getDistance(%w(A2 A1 A3), %w(A1 X1 A2 X2 A3 X3))
# -> 8
# Because (0, 2[2], 1[1], 3[2], 0[3]) -> 2 + 1 + 2 + 3 = 8

-module(devto6).
-export([find_distance/1]).

find_distance([B, C | Rest]) ->
    TotalDist = B,
    A = math:sqrt(C * C - B * B),
    find_distance(TotalDist + A, C, Rest).

find_distance(TotalDist, B, [C | Rest]) ->
    A = math:sqrt(C * C - B * B),
    find_distance(TotalDist + A, C, Rest);
find_distance(TotalDist, C, []) ->
    TotalDist + C.

enum Map {
    X1 = 100.0,
    X2 = 200.0,
    X3 = 250.0,
    X4 = 300.0,
}

const grannyFriends = [
    ['A1', 'X1'],
    ['A2', 'X2'],
    ['A3', 'X3'],
    ['A4', 'X4'],
];

export default (friends: string[]): number => {
    return friends
        .map(f => {
            for (const gf of grannyFriends) {
                if (gf.includes(f)) {
                    return Map[gf[1]];
                }
            }
            return 0;
        })
        .reduce((acc, curr) => (curr > 0 ? acc + (curr - acc) : acc), 0);
};

import grannyTrip from './help-your-granny';

describe('tdd granny trip', () => {
    test('should calculate distances', () => {
        expect(grannyTrip(['A1', 'A2', 'A3', 'A4', 'A5'])).toEqual(300);
        expect(grannyTrip(['A1', 'A2', 'A3'])).toEqual(250);
        expect(grannyTrip(['A1', 'A2', 'A4'])).toEqual(300);
    });
});

$friends = [["A1", "X1"], ["A2", "X2"], ["A3", "X3"], ["A4", "X4"]];
$distances = [["X1", 100], ["X2", 200], ["X3", 350], ["X4", 420]];

$distances = array_reduce($distances, function($x, $y){
    $x[$y[0]] = $y[1]; 
    return $x;
});

function getTotalDistance($friends, $distances){
    $total = 0;
    for($x = 0; $x < count($friends); $x++){
        if(count($friends[$x]) === 2){
            $total += ($distances[$friends[$x][1]] * 2);
        }
    }
    return $total;
}
echo getTotalDistance($friends, $distances);

package utils

import (
    "errors"
    "math"
)

type CityDistance struct {
    City string
    Distance float64
}

func VisitFriend(friendsToVisit []string, friendsCities [][]string, cityDistances []CityDistance) (int, error) {
    totalDistance := 0.0

    var lastCityName string
    for _, friend := range friendsToVisit {
        friendCity, e := findFriendCity(friend, friendsCities)

        if e != nil {
            return 0, e
        }

        if lastCityName == "" {
            distanceToCity, e := findDistanceToCity(friendCity, cityDistances)

            if e != nil {
                return 0, e
            }

            totalDistance += distanceToCity
        } else {
            distanceBetweenCities, e := findDistanceBetweenCities(lastCityName, friendCity, cityDistances)

            if e != nil {
                return 0, e
            }

            totalDistance += distanceBetweenCities
        }

        lastCityName = friendCity
    }
    distanceBackToHome, _ := findDistanceToCity(lastCityName, cityDistances)

    totalDistance += distanceBackToHome
    return int(math.Floor(totalDistance)), nil
}

func findDistanceToCity(city string, cityDistances []CityDistance) (float64, error) {
    for _, cityDistance := range cityDistances {
        cityName := cityDistance.City
        distance := cityDistance.Distance

        if cityName == city {
            return distance, nil
        }
    }

    return 0, errors.New("Didn't find city")
}

func findDistanceBetweenCities(fromCity string, toCity string, cityDistances []CityDistance) (float64, error) {
    totalDistance := 0.0

    lastDistance := 0.0;
    for _, cityDistance := range cityDistances {
        city := cityDistance.City
        distance := cityDistance.Distance

        if lastDistance > 0 {
            totalDistance += math.Sqrt((lastDistance * lastDistance) + (distance * distance))
        }

        if (city == fromCity || city == toCity) && lastDistance > 0 {
            return totalDistance, nil
        }

        if (city == fromCity || city == toCity) || lastDistance > 0 {
            lastDistance = distance
        }
    }

    return 0, errors.New("Didn't find city")
}

func findFriendCity(friend string, friendCities [][]string) (string, error) {
    for _, friendCity := range friendCities {
        if friend == friendCity[0] {
            return friendCity[1], nil
        }
    }

    return "", errors.New("Didn't found city for friend!")
}

let distanceReferences = [ "X1": 100.0, "X2": 200.0, "X3": 250.0, "X4": 300.0 ]
let friendsReferences = [ "A1": "X1", "A2": "X2", "A3": "X3", "A4": "X4" ]
let friendsOrder = [ "A1", "A2", "A3", "A4", "A5"]

func grandmaTravel(friendsToVisit: [String]) -> Int {
    func distanceBetween(firstPoint: String, to secondPoint: String) -> Int {
        let first = distanceReferences.first {
            $0.key == firstPoint
        }

        let second = distanceReferences.first {
            $0.key == secondPoint
        }

        guard let distanceToFirst = first?.value, let distanceToSecond = second?.value
            else { return 0 }
        let result = (pow(distanceToSecond, 2) - pow(distanceToFirst, 2)).squareRoot()

        return Int(result.rounded())
    }

    var distance = 0
    var points = friendsToVisit.compactMap {
        friendsReferences[$0]
    }
    var currentPoint = points.removeFirst()

    // X0 to fist town
    distance += Int(distanceReferences[currentPoint] ?? 0)

    points.forEach {
        distance += distanceBetween(firstPoint: currentPoint, to: $0)
        currentPoint = $0
    }

    // last town to X0
    distance += Int(distanceReferences[currentPoint] ?? 0)

    return distance
}

grandmaTravel(friendsToVisit: friendsOrder)

let friends = [["A1", "X1"], ["A2", "X2"], ["A3", "X3"], ["A4", "X4"]];
let distances = [["X1", 100.0], ["X2", 200.0], ["X3", 250.0], ["X4", 300.0]];

// transform the array into an object to make it easier to process later
// solution from https://stackoverflow.com/q/26454655/3695983
distances = distances.reduce(function(p, c) { p[c[0]]=c[1]; return p; }, {});

function calculateDistance(friends, distances) {
  let total = 0;
  for (let x = 0; x < friends.length; x++) 
    if (friends[x].length === 2) 
      total += (distances[friends[x][1]] * 2);
  return total;
}

let distances = { "X1": 100.0, "X2": 200.0, "X3": 250.0, "X4": 300.0 };
let friends = [ ["A1", "X1"], ["A2", "X2"], ["A3", "X3"], ["A4", "X4"] ];

const calculateDistance = (friends, distances) => friends.reduce((acc, curr) => curr.length === 2 ? acc + (distances[curr[1]] * 2) : acc, 0);