0048.旋转图像

https://leetcode.cn/problems/rotate-image/

方法一：遍历

时间复杂度 $O(n^2)$，空间复杂度 $O(1)$。

func rotate(matrix [][]int) {
	n := len(matrix)
	for i := 0; i < n; i++ {
		for j := 0; j < i; j++ {
			matrix[i][j], matrix[j][i] = matrix[j][i], matrix[i][j]
		}
	}
	for i := 0; i < n; i++ {
		for j, k := 0, n-1; j < k; j, k = j+1, k-1 {
			matrix[i][j], matrix[i][k] = matrix[i][k], matrix[i][j]
		}
	}
}

impl Solution {
    pub fn rotate(matrix: &mut Vec<Vec<i32>>) {
        let n = matrix.len();
        for i in 0..n {
            for j in i..n {
                let tmp = matrix[i][j];
                matrix[i][j] = matrix[j][i];
                matrix[j][i] = tmp;
            }
        }
        for i in 0..n {
            let (mut j, mut k) = (0, n - 1);
            while j < k {
                matrix[i].swap(j, k);
                j += 1;
                k -= 1;
            }
        }
    }
}