题解 | #顺时针旋转矩阵#

/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 * 
 * @param mat int整型二维数组 
 * @param n int整型 
 * @return int整型二维数组
 */
export function rotateMatrix(mat: number[][], n: number): number[][] {
    const len: number = mat.length
    
    // 矩阵对角转置
    for (let i = 0; i < len; i++ ) {
        for (let j = 0; j < i; j++ ) {
            const temp = mat[i][j]
            mat[i][j] = mat[j][i]
            mat[j][i] = temp
        }
    }
    
    // 每行翻转
    for (let i = 0; i < len; i++ ) {
        for (let j = 0; j < len / 2; j++ ) {
            const temp = mat[i][j]
            mat[i][j] = mat[i][len - j - 1]
            mat[i][len - j - 1] = temp
        }
    }
  
    return mat
}