题解 | #顺时针旋转矩阵#

import java.util.*;

public class Solution {
    public int[][] rotateMatrix(int[][] mat, int n) {
        int[][] result = new int[mat.length][mat.length];
        Stack<Integer> newRow;
        for (int i = 0; i < mat.length; i++) {
            newRow = getColumn(mat, i);
            for (int j = 0; j < mat.length; j++) {
                result[i][j] = newRow.pop();
            }
        }
        return result;
    }

    private Stack<Integer> getColumn(int[][] mat, int col) {
        Stack<Integer> newRow = new Stack<>();
        for (int i = 0; i < mat.length; i++) {
            for (int j = 0; j < mat.length; j++) {
                if (j == col) {
                    newRow.push(mat[i][j]);
                }
            }
        }

        return newRow;

    }
}