题解 | #蛇形矩阵#

import java.util.*;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
  public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
    // 模拟蛇行
    int lineTotal = in.nextInt();
    int[][] aa = new int[lineTotal][lineTotal];

    int lineCount = 0;
    int num = 1;
    while (lineCount < lineTotal) {
      int elementTotal = lineCount + 1;
      int elementCount = 0;
      int tmpLineCount = lineCount;
      while (elementCount < elementTotal) {
        aa[tmpLineCount][elementCount] = num;
        tmpLineCount--;
        elementCount++;
        num++;
      }
      lineCount++;
    }

    for (int i = 0; i < lineTotal; i++) {
      StringBuilder sb = new StringBuilder();
      for (int j = 0 ; j < lineTotal; j++) {
        if (aa[i][j] != 0) {
          sb.append(aa[i][j]+" ");
        }
      }
      System.out.println(sb.toString().trim());
    }
  }
}