Fillomino 2

题意翻译

给定长度为 $n\space (1 \le n \le 500)$ 的排列 $p$，要求构造一个三角形，满足以下条件： 1. 三角形共 $n$ 行，第 $i$ 行有 $i$ 个数。第 $i$ 行最后一个数是 $p_i$。 2. 接下来构造 $n$ 个连通块。对于第 $x \space (1 \le x \le n)$ 个连通块,每个元素、连通块大小都必须等于 $x$。 3. 三角形每个格子必须恰好填一个数。 ------------ 输入 $n$、$p$，输出该三角形。

题目描述

Fillomino is a classic logic puzzle. (You do not need to know Fillomino in order to solve this problem.) In one classroom in Yunqi town, some volunteers are playing a board game variant of it: Consider an $ n $ by $ n $ chessboard. Its rows are numbered from $ 1 $ to $ n $ from the top to the bottom. Its columns are numbered from $ 1 $ to $ n $ from the left to the right. A cell on an intersection of $ x $ -th row and $ y $ -th column is denoted $ (x, y) $ . The main diagonal of the chessboard is cells $ (x, x) $ for all $ 1 \le x \le n $ . A permutation of $ \{1, 2, 3, \dots, n\} $ is written on the main diagonal of the chessboard. There is exactly one number written on each of the cells. The problem is to partition the cells under and on the main diagonal (there are exactly $ 1+2+ \ldots +n $ such cells) into $ n $ connected regions satisfying the following constraints: 1. Every region should be connected. That means that we can move from any cell of a region to any other cell of the same region visiting only cells of the same region and moving from a cell to an adjacent cell. 2. The $ x $ -th region should contain cell on the main diagonal with number $ x $ for all $ 1\le x\le n $ . 3. The number of cells that belong to the $ x $ -th region should be equal to $ x $ for all $ 1\le x\le n $ . 4. Each cell under and on the main diagonal should belong to exactly one region.

输入输出格式

输入格式

The first line contains a single integer $ n $ ( $ 1\le n \le 500 $ ) denoting the size of the chessboard. The second line contains $ n $ integers $ p_1 $ , $ p_2 $ , ..., $ p_n $ . $ p_i $ is the number written on cell $ (i, i) $ . It is guaranteed that each integer from $ \{1, \ldots, n\} $ appears exactly once in $ p_1 $ , ..., $ p_n $ .

输出格式

If no solution exists, output $ -1 $ . Otherwise, output $ n $ lines. The $ i $ -th line should contain $ i $ numbers. The $ j $ -th number on the $ i $ -th line should be $ x $ if cell $ (i, j) $ belongs to the the region with $ x $ cells.

输入输出样例

输入样例 #1

3
2 3 1

输出样例 #1

2
2 3
3 3 1

输入样例 #2

5
1 2 3 4 5

输出样例 #2

1
2 2
3 3 3
4 4 4 4
5 5 5 5 5

说明

The solutions to the examples are illustrated in the following pictures: