import Foundation
func generateSpiralMatrix(n: Int) -> [[Int]] {
// Initialize n x n matrix with zeros
var matrix = Array(repeating: Array(repeating: 0, count: n), count: n)
// Boundary variables
var top = 0
var bottom = n - 1
var left = 0
var right = n - 1
var num = 1
while top <= bottom && left <= right {
// Fill top row from left to right
for col in left...right {
matrix[top][col] = num
num += 1
}
top += 1
// Fill right column from top to bottom
for row in top...bottom {
matrix[row][right] = num
num += 1
}
right -= 1
// Fill bottom row from right to left (if there are remaining rows)
if top <= bottom && left <= right {
for col in stride(from: right, through: left, by: -1) {
matrix[bottom][col] = num
num += 1
}
bottom -= 1
}
// Fill left column from bottom to top (if there are remaining columns)
if left <= right && top <= bottom {
for row in stride(from: bottom, through: top, by: -1) {
matrix[row][left] = num
num += 1
}
left += 1
}
}
return matrix
}
func printMatrix(_ matrix: [[Int]]) {
let n = matrix.count
let maxWidth = String(n * n).count
for row in matrix {
let formattedRow = row.map { String(format: "%\(maxWidth)d", $0) }.joined(separator: " ")
print(formattedRow)
}
}
let n = 4
let spiralMatrix = generateSpiralMatrix(n: n)
print("Spiral Matrix (\(n)x\(n)):")
printMatrix(spiralMatrix)
/*
run:
Spiral Matrix (4x4):
1 2 3 4
12 13 14 5
11 16 15 6
10 9 8 7
*/
