Increment Values in an array (Swift)

Question

So I'm in class and I'm trying to make our thing a little easier. We are trying to make a Q*bert like landscape, and we are using arrays. I'm trying to make it a lot shorter and repeatable. So I have:

let allCoordinate = world.allPossibleCoordinates
let coordinaterow = coordinate.row
var coordinaterow = 3

while coodinaterow != 8 {

    var heights: [Int] = [0,0,0,0,0,0,0,0,1]

    var index = 0

    for coordinate in allCoordinates {
        if coordinate.row ==3 {
            if index == height.count {
                index = 0
            }

            for i in 0...heights[index] {
                world.place(Block(), at: coordinate)
            }
            index += 1
        }
    }

    allCoordinate += 1
    coordinaterow += 1
}

How would Increment the heights array like:

0,0,0,0,0,0,0,0,1 -- 0,0,0,0,0,0,0,1,2 -- 0,0,0,0,0,0,1,2,3

and so forth

Answer 1

You can iterate your collection indices reversed and check if each element is equal to zero, increase and break the iteration, otherwise just increase it:

var heights: [Int] = [0,0,0,0,0,0,0,1,2]

for index in heights.indices.reversed() {
    if heights[index] == 0 {
        heights[index] += 1
        break
    }
    heights[index] += 1
}

print(heights)   // [0, 0, 0, 0, 0, 0, 1, 2, 3]

Answer 2

try this:

func increment(array: [Int]) -> [Int] {

    var result = array

    var lastValue = false

    result = result.reversed().map { value in
        if lastValue { return 0 }
        if value == 0 {
            lastValue = true
            return 1
        }
        return value + 1
    }
    result.reverse()
    return result
}

Answer 3

An alternative approach to getting a height ramp (which seems to be what you are trying to achieve) is not to think about incrementing an existing array, but creating it. The following code demonstrates this:

let heightCount = 10
let rampCount = heightCount // can be any value <= heightCount
for ramp in 1...rampCount {
    let rampHeights = [Int](repeating: 0, count: heightCount-ramp) + [Int](1...ramp)
    print(rampHeights)
}

The output from this code will be

[0, 0, 0, 0, 0, 0, 0, 0, 0, 1]
[0, 0, 0, 0, 0, 0, 0, 0, 1, 2]
[0, 0, 0, 0, 0, 0, 0, 1, 2, 3]
[0, 0, 0, 0, 0, 0, 1, 2, 3, 4]
[0, 0, 0, 0, 0, 1, 2, 3, 4, 5]
[0, 0, 0, 0, 1, 2, 3, 4, 5, 6]
[0, 0, 0, 1, 2, 3, 4, 5, 6, 7]
[0, 0, 1, 2, 3, 4, 5, 6, 7, 8]
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

As you can see the heightCount value determines the overall length of the array and within the loop the ramp value determines the number of non-zero values in the ramp .

Note: the loop is just for demonstration purposes. The key line of code is:

let rampHeights = [Int](repeating: 0, count: heightCount-ramp) +
                  [Int](1...ramp)

which you can put wherever you need in your code. You just need to make sure heightCount and ramp have appropriate values.