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tanveer/spiralMatrixII

Created January 10, 2021 01:28
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Revisions

  1. tanveer created this gist Jan 10, 2021.
    65 changes: 65 additions & 0 deletions spiralMatrixII
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,65 @@
    func generateMatrix(_ n: Int) -> [[Int]] {
    var maxRow = n
    var maxCol = n

    var startRow = 0
    var startCol = 0

    let currRow = 0
    let currCol = 0
    var direction = "R"
    var valueCounter = 1
    var result = [[Int]](repeating: [Int](repeating: 0, count: n), count: n)

    while currRow < n && currCol < n && valueCounter < n * n + 1 {
    if direction == "R" {
    for currCol in startCol..<maxCol {
    if result[currRow][currCol] == 0 {
    result[currRow][currCol] = valueCounter
    valueCounter += 1
    }
    }

    startRow += 1
    direction = "D"
    }

    if direction == "D" {
    for row in startRow..<maxRow {
    if result[row][currCol] == 0 {
    result[row][currCol] = valueCounter
    valueCounter += 1
    }
    }

    maxCol -= 1
    direction = "L"
    }

    if direction == "U" {
    for row in stride(from: maxRow, through: startRow, by: -1) {
    if result[row][currCol] == 0 {
    result[row][currCol] = valueCounter
    valueCounter += 1
    }
    }

    startCol += 1
    direction = "R"
    }

    if direction == "L" {
    for col in stride(from: maxCol, through: startCol, by: -1) {
    if result[currRow][col] == 0 {
    result[currRow][col] = valueCounter
    valueCounter += 1
    }
    }

    maxRow -= 1
    direction = "U"
    }
    }

    return result
    }