Implementation of /r/DailyProgrammer Challenge #168 in Swift

MapSurvey.swift

// [6/25/2014] Challenge #168 [Intermediate] Block Count, Length & Area : dailyprogrammer http://www.reddit.com/r/dailyprogrammer/comments/291x9h/6252014_challenge_168_intermediate_block_count/
// Author: Amit Jain
// Date: 08/08/2014

import Cocoa

struct Tile {
    let char: Character // char represented
    let x: Int // x position
    let y: Int // y position
    var cScore = 4 // number of sides to be counted in circumference calculation. Strats with 4, reduced by 2 on every successful match
    var blockIndex: Int // index of representative block
}

struct Block {
    var index: Int // index of the block
    let char: Character // representating char
    var rank: Int // number of elements
    var count: Int // number of blocks of this type
    var cScore = 0 // cScore of the whole block
    var circumference: Int = 0
    var area: Int = 0
}

class Surveyor {
    
    var rowSize = 0
    
    func earmarkMap(map: String) -> [Tile] {
        var earmarkedMap: [Tile] = []
        let rows = map.componentsSeparatedByCharactersInSet(NSCharacterSet.newlineCharacterSet())
        rowSize = rows[0].lengthOfBytesUsingEncoding(NSUTF8StringEncoding) // number of tiles in a row
        for y in 0 ..< rows.count {
            var row = rows[y]
            var x = 0
            for char in row {
                let tile = Tile(char: char, x: x, y: y, cScore: 4, blockIndex: -1)
                earmarkedMap += [tile]
                ++x
            }
        }
        
        return earmarkedMap
    }
    
    func blocksFromMapTiles(tiles: [Tile]) -> [Block]{
        var earmarkedTiles = tiles
        var blocks = [Int: Block]()
        for index in 0 ..< earmarkedTiles.count {
            var tile = earmarkedTiles[index]
            let x = tile.x
            let y = tile.y
            
            if x == 0 || y == 0 { // account for tiles on the top and left edges
                if x == 0 && y == 0 { // first tile
                    // create a new block with tile
                    var block = Block(index: blocks.count + 1, char: tile.char, rank: 1, count: 1, cScore: tile.cScore, circumference: 0, area: 0)
                    blocks[blocks.count + 1] = block
                    // update the tile with its index
                    tile.blockIndex = block.index
                    // add the tile back to the earmarked map
                    earmarkedTiles[index] = tile
                } else if x == 0 && y != 0 { // left edge
                    let topTile = earmarkedTiles[index - rowSize]
                    if tile.char == topTile.char {
                        // update the tile with its index and put it back into the map
                        tile.cScore -= 2
                        tile.blockIndex = topTile.blockIndex
                        earmarkedTiles[index] = tile
                        // add the tile to the top tile's block
                        blocks[topTile.blockIndex]?.rank += 1
                        // update the block's cScore
                        blocks[topTile.blockIndex]?.cScore += tile.cScore
                    } else {
                        // create a new block with tile
                        var block = Block(index: blocks.count + 1, char: tile.char, rank: 1, count: 1,  cScore: tile.cScore, circumference: 0, area: 0)
                        blocks[blocks.count + 1] = block
                        // update the tile with its index
                        tile.blockIndex = block.index
                        // add the tile back to the earmarked map
                        earmarkedTiles[index] = tile
                    }
                } else if x != 0 && y == 0 { // top edge
                    let leftTile = earmarkedTiles[index - 1]
                    if tile.char == leftTile.char {
                        // update the tile with its index and put it back into the map
                        tile.cScore -= 2
                        tile.blockIndex = leftTile.blockIndex
                        earmarkedTiles[index] = tile
                        // add the tile to the left tile's block
                        blocks[leftTile.blockIndex]?.rank += 1
                        // update the block's cScore
                        blocks[leftTile.blockIndex]?.cScore += tile.cScore
                    } else {
                        // create a new block with tile
                        var block = Block(index: blocks.count + 1, char: tile.char, rank: 1, count: 1, cScore: tile.cScore, circumference: 0, area: 0)
                        blocks[blocks.count + 1] = block
                        // update the tile with its index
                        tile.blockIndex = block.index
                        // add the tile back to the earmarked map
                        earmarkedTiles[index] = tile
                    }
                }
            } else {
                // tile to the left will have the index 1 less than current tile
                let leftTile = earmarkedTiles[index - 1]
                // tile to the top will have index sum of x and y
                let topTile = earmarkedTiles[index - rowSize]
                if (tile.char != leftTile.char) && (tile.char != topTile.char) {
                    // create a new block with tile
                    var block = Block(index: blocks.count + 1, char: tile.char, rank: 1, count: 1, cScore: tile.cScore, circumference: 0, area: 0)
                    blocks[blocks.count + 1] = block
                    // update the tile with its index
                    tile.blockIndex = block.index
                    // add the tile back to the earmarked map
                    earmarkedTiles[index] = tile
                } else if (tile.char == leftTile.char) && (tile.char != topTile.char) {
                    // update the tile with its index and put it back into the map
                    tile.cScore -= 2
                    tile.blockIndex = leftTile.blockIndex
                    earmarkedTiles[index] = tile
                    // add the tile to the left tile's block
                    blocks[leftTile.blockIndex]?.rank += 1
                    // update the block's cScore
                    blocks[leftTile.blockIndex]?.cScore += tile.cScore
                } else if (tile.char != leftTile.char) && (tile.char == topTile.char) {
                    // update the tile with its index and put it back into the map
                    tile.cScore -= 2
                    tile.blockIndex = topTile.blockIndex
                    earmarkedTiles[index] = tile
                    // add the tile to the top tile's block
                    blocks[topTile.blockIndex]?.rank += 1
                    // update the block's cScore
                    blocks[topTile.blockIndex]?.cScore += tile.cScore
                } else if (tile.char == leftTile.char) && (tile.char == topTile.char) {
                    let topTileBlockIndex = topTile.blockIndex
                    let leftTileBlockIndex = leftTile.blockIndex
                    let topBlockRank = blocks[topTileBlockIndex]!.rank
                    let leftBlockRank = blocks[leftTileBlockIndex]!.rank
                    if topBlockRank > leftBlockRank {
                        // merge left tile's parent block into top tile's block
                        blocks[topTileBlockIndex]?.rank += leftBlockRank
                        blocks[topTileBlockIndex]?.cScore += blocks[leftTileBlockIndex]!.cScore
                        // get rid of the extra block
                        blocks[leftTileBlockIndex] = nil
                        // update the tile with its index and put it back into the map
                        tile.cScore -= 4
                        tile.blockIndex = topTile.blockIndex
                        earmarkedTiles[index] = tile
                        // add the main tile to the top tile's block
                        blocks[topTile.blockIndex]?.rank += 1
                        // update the block's cScore
                        blocks[topTile.blockIndex]?.cScore += tile.cScore
                    } else if topBlockRank > leftBlockRank {
                        // merge left tile's parent block into top tile's block
                        blocks[leftTileBlockIndex]?.rank += topBlockRank
                        blocks[leftTileBlockIndex]?.cScore += blocks[topTileBlockIndex]!.cScore
                        // get rid of the extra block
                        blocks[topTileBlockIndex] = nil
                        // update the tile with its index and put it back into the map
                        tile.cScore -= 4
                        tile.blockIndex = leftTile.blockIndex
                        earmarkedTiles[index] = tile
                        // add the main tile to the left tile's block
                        blocks[leftTile.blockIndex]?.rank += 1
                        // update the block's cScore
                        blocks[leftTile.blockIndex]?.cScore += tile.cScore
                    } else { // when both, top and left, tiles belong to the same block
                        // update the tile with its index and put it back into the map
                        tile.cScore -= 4
                        tile.blockIndex = leftTile.blockIndex
                        earmarkedTiles[index] = tile
                        // add the main tile to the left tile's block
                        blocks[leftTile.blockIndex]?.rank += 1
                        // update the block's cScore
                        blocks[leftTile.blockIndex]?.cScore += tile.cScore
                    }
                }
            }
        }
        
        var allBlocks = [Block]()
        for (index, block) in blocks {
            allBlocks += [block]
        }
        
        for outerIndex in 0 ..< allBlocks.count {
            var referenceBlock = allBlocks[outerIndex]
            for innerIndex in outerIndex+1 ..< allBlocks.count {
                var block = allBlocks[innerIndex]
                if referenceBlock.char == block.char && block.count > 0{
                    ++referenceBlock.count //increase the count on the reference block
                    referenceBlock.rank += block.rank
                    referenceBlock.cScore += block.cScore
                    block.count = 0 //discount the matched block
                    // put blocks back into the array
                    allBlocks[outerIndex] = referenceBlock
                    allBlocks[innerIndex] = block
                }
            }
        }
        
        let flattenedBlocks = allBlocks.filter{ $0.count > 0 }
        
        return flattenedBlocks
    }
    
    func metricsForBlocks(b: [Block]) -> [Block] {
        var blocks = b
        var circumference = 0
        var area = 0
        for i in 0 ..< blocks.count {
            var block = blocks[i]
            block.circumference = block.cScore * 10
            block.area = block.rank * 100
            blocks[i] = block
        }
        
        return blocks
    }
    
    func surveyMap(map: String) {
        let startTime = NSDate.date()
        var blocks = metricsForBlocks(blocksFromMapTiles(earmarkMap(map)))
        println("\n----Survey Data----\n")
        for block in blocks {
            println("\(block.char) | x\(block.count) | \(block.circumference) ft, \(block.area) sqft")
        }
        let endTime = NSDate.date()
        let duration = endTime.timeIntervalSinceDate(startTime)
        println("\nRuntime: \(duration)")
    }
}

let map = "ooooooooooooooooooooooDDDDDooooooooooooooooooooooooooooo\nooooooooooooooooooooooDDDDDooooooooooooooooooooooooooooo\nooo##################o#####o#########################ooo\no@o##################o#####o#########################ooo\nooo##################o#####o#########################oTo\no@o##################################################ooo\nooo##################################################oTo\no@o############ccccccccccccccccccccccc###############ooo\npppppppppppppppcOOOOOOOOOOOOOOOOOOOOOc###############oTo\no@o############cOBBBBBBBBBBBBBBBBBBBOc###############ooo\nooo####V#######cOBBBBBBBBBBBBBBBBBBBOc###############oTo\no@o####V#######cOBBBBBBBBBBBBBBBBBBBOc###############ooo\nooo####V#######cOBBBBBBBBBBBBBBBBBBBOcpppppppppppppppppp\no@o####V#######cOBBBBBBBBBBBBBBBBBBBOc###############ooo\nooo####V#######cOBBBBBBBBBBBBBBBBBBBOc######v########oTo\no@o####V#######cOBBBBBBBBBBBBBBBBBBBOc######v########ooo\nooo####V#######cOOOOOOOOOOOOOOOOOOOOOc######v########oTo\no@o####V#######ccccccccccccccccccccccc######v########ooo\nooo####V#######ppppppppppppppppppppppp######v########oTo\no@o############ppppppppppppppppppppppp###############ooo\noooooooooooooooooooooooooooooooooooooooooooooooooooooooo\noooooooooooooooooooooooooooooooooooooooooooooooooooooooo"

let surveyor = Surveyor()
surveyor.surveyMap(map)