LeetCode/com/zerroi/leetcode/Three17/Rotate.java

package com.zerroi.leetcode.Three17;

import java.util.Arrays;

public class Rotate {
    public static void main(String[] args) {
        int[][] matrix = new int[][]{{5,1,9,11},{2,4,8,10},{13,3,6,7},{15,14,12,16}};
        SolutionFirst solutionFirst = new SolutionFirst();
        solutionFirst.rotate(matrix);
    }
}
/*
* 给定一个 n × n 的二维矩阵 matrix 表示一个图像。请你将图像顺时针旋转 90 度。

* */
class SolutionFirst {
    public void rotate(int[][] matrix) {
        int n = matrix.length;
        int[][] res = new int[n][n];
        int indexCol;
        int indexRow = 0;
        for (int i = n - 1; i >= 0; i--) {
            indexCol = n - 1;
            for (int j = n - 1; j >= 0; j--) {
                res[indexCol][indexRow] = matrix[i][j];
                indexCol--;
            }
            indexRow++;
        }

        for (int i = 0; i < n; i++) {
            System.arraycopy(res[i], 0, matrix[i], 0, n);
        }
    }
}