2021-09-29

import java.util.Scanner;

 class MatrixTest {

     public static void main(String[] args) {
         System.out.println("输入矩阵的阶：");
         Scanner scanner = new Scanner(System.in);
         int n = scanner.nextInt();

         way(n);

     }

     public static void way(int n) {
         int[][] ints = new int[n][n];
         int count = 1;
         boolean up = true;
         //左上三角形
         for (int i = 0; i < n; i++) {//i是下标和

             if (up) {
                 for (int j = 0; j <= i; j++) {
                     ints[j][i - j] = count++;
                 }
             } else {
                 for (int j = 0; j < i; j++) {
                     ints[i - j][j] = count++;
                 }
                 up = !up;
             }
         }

         //右下角三角形
         for (int i = n; i < 2 * n - 1; i++) {

             if (up) {
                 for (int j = i - n + 1; j < n; j++) {
                     ints[j][i - j] = count++;
                 }
             } else {
                 for (int j = i - n + 1; j < n; j++) {
                     ints[i - j][j] = count++;
                 }
                 up = !up;
             }
         }


         System.out.println("第一种");
         printable(ints);

         MatrixTest.exchangeMatrix(ints);
         System.out.println("第二种");
         printable(ints);

     }

     //将对角线左右两边对称的数字对换位置
     public static int[][] exchangeMatrix(int[][] ints) {
         for (int i = 0; i < ints.length; i++) {
             for (int j = 0; j <= i; j++) {
                 int temp = ints[i][j];
                 ints[i][j] = ints[j][i];
                 ints[j][i] = temp;
             }
         }
         return ints;
     }

     //打印
     public static void printable(int[][] ints) {
         for (int i = 0; i < ints.length; i++) {
             for (int j = 0; j < ints[i].length; j++) {
                 System.out.print(" " + ints[i][j]);
             }
             System.out.println();
         }


     }
 }