Java 二維陣列列旋轉為行

Java 二維陣列將列row的位置轉為行col的位置方法如下。

int[][] m = {{1,2,3}, {4,5,6}, {7,8,9}};
int c = m[0].length;
int r = m.length;

int[][] mr = new int[c][r];
for (int i = 0; i < c; i++) {
    for (int j = 0; j < r; j++) {
        mr[i][j] = m[j][i];
    }
}
System.out.println(Arrays.deepToString(m));  // [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
System.out.println(Arrays.deepToString(mr)); // [[1, 4, 7], [2, 5, 8], [3, 6, 9]]