![Uploading 屏幕快照 2016-08-05 11.28.09_715873.png . . .]##Problem Description
You are given an n x n 2D matrix representing an image.
Rotate the image by 90 degrees (clockwise).
Follow up:
Could you do this in-place?
Analyze
Code
class Solution {
func rotate(inout matrix: [[Int]]) {
let lines = matrix.count
func swapInMatrix(left: (Int, Int), right: (Int, Int)) {
let temp = matrix[left.0][left.1]
matrix[left.0][left.1] = matrix[right.0][right.1]
matrix[right.0][right.1] = temp
}
for line in 0..<lines {
for column in 0..<lines-line {
swapInMatrix((line, column), right: (lines-1-column, lines-1-line))
}
}
for line in 0..<lines/2 {
for column in 0..<lines {
swapInMatrix((line, column), right: (lines-1-line, column))
}
}
}
}
