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Hackerland Radio Transmitters

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  • jono_reshef
     + 0 comments

    In Python, don't forget to run set on the house locations ("x") first. We only need to order the unique house locations.

  • anatoltbcm
     + 0 comments

    Java. Not the best solution, I think, but it works.

    public static int hackerlandRadioTransmitters(List<Integer> x, int k) {
    x.sort(Integer::compareTo);
    int count = 1;
    int currentBranchStart = x.get(0);
    boolean isLeftBranch = true;

    for (int i = 1; i < x.size(); i++) {
        int currentLocation = x.get(i);
        int prevLocation = x.get(i - 1);

        if (currentLocation - prevLocation > k) {
            count++;
            currentBranchStart = currentLocation;
            isLeftBranch = true;
            continue;
        }

        if (currentLocation - currentBranchStart > k) {
            if (isLeftBranch) {
                currentBranchStart = prevLocation;
            } else {
                currentBranchStart = currentLocation;
                count++;
            }
            isLeftBranch = !isLeftBranch;
        }
    }

    return count;
}

  • cherkashin_i_a
     + 0 comments
    def hackerlandRadioTransmitters(x, k):
    locations = sorted(x)
    station_location = first_house_outside_coverage = one_side_covered = two_side_coverage_counter = 0

    while station_location < len(locations):
        station_location_0 = station_location

        while first_house_outside_coverage < len(locations) and locations[first_house_outside_coverage] <= locations[station_location] + k:
            first_house_outside_coverage += 1

        if first_house_outside_coverage == station_location_0 + 1 or one_side_covered:
            station_location = first_house_outside_coverage
            two_side_coverage_counter += 1
            one_side_covered = 0
        else:
            station_location = first_house_outside_coverage - 1
            one_side_covered = 1

    return two_side_coverage_counter

  • ptdoantrinh2691
     + 1 comment

    Test case #2: 7 2 9 5 4 2 6 15 12

    Expected output: 4

    I think the result should be 3. When sorting: [2, 4, 5, 6, 9, 12, 15] Result is: [2, 4, 5, 6] -> 1 transmitter [9, 12] -> 1 transmitter [15] -> 1 transmitter Total 3 transmitters. Any help? Thank you!

  • williamzhang_wcz
     + 0 comments
    def hackerlandRadioTransmitters(x, k):
    t=0 #number of transmitters
    ind=0 #our location in Hackerland
    while ind<max(x): #Loops through the cities in list x
        if ind+1 not in x:
            ind+=1 #This makes sure we don’t place transmitters in places where there are no houses
        else:
            while ind+k+1 not in x:
                ind-=1 #This makes sure that the center is one of the houses
            t+=1 #Adds a transmitter
            ind+=(2*k+1) #skips all the locations where the transmitter is reached
    return t #returns the amount of of transmitters