题解 | 球格模型（简单版）

import java.util.Scanner;

// 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);
        int n = in.nextInt();
        int m = in.nextInt();
        long k = in.nextLong();

        if(k < Math.max(n, m)) {
            System.out.println("-1");
            return;
        }

        long[][] grid = new long[n][m];
        long used = 0;

        // 1.填充对角线
        int minNM = Math.min(n, m);
        for(int i = 0; i < minNM; i++) {
            grid[i][i] = 1;
            used++;
        }

        // 填充剩余的行或列
        // 2.填充剩余的行，若 minNM = n 则该循环执行0次
        for(int i = minNM; i < n; i++) {
            grid[i][0] = 1;
            used++;
        }
        
        // 3.填充剩余的列，若 minNM = m 则该循环执行0次
        for(int j = minNM; j < m; j++) {
            grid[0][j] = 1;
            used++;
        }

        // 4.多余的球放 (0, 0)
        grid[0][0] += (k - used);

        // 输出矩阵
        StringBuilder sb = new StringBuilder();
        for(int i = 0; i < n; i++) {
            for(int j = 0; j < m; j++) {
                sb.append(grid[i][j])
                .append(j == m - 1 ? "" : " ");
            }
            sb.append("\n");
        }

        System.out.println(sb);
    }
}