题解 | #蛇形矩阵#

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNextInt()) {
            int n = in.nextInt();
            int[][] mat = new int[n][n];
            int i = 0, j = 0;
            int val = 1;
            // 按照数值顺序填写
            while (i < n && j < n) {
                mat[i][j] = val;
                ++val;
                if (i == 0) { // 到达斜上角，回到第1列，因为是对称关系，行就是列+1
                    i = j + 1;
                    j = 0;
                } else { // 否则，沿斜边向右上移动
                    --i;
                    ++j;
                }
            }
            for (int p = 0; p < n; ++p) {
                for (int q = 0; q < n - p; ++q) {
                    System.out.print(mat[p][q] + " ");
                }
                System.out.println();
            }
        }
    }
}