Codeforces Round 812 (Div. 2)
E
Cross Swapping
Codeforces
2400
原题
← DF →
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You are given a square matrix $A$ of size $n \times n$ whose elements are integers. We will denote the element on the intersection of the $i$-th row and the $j$-th column as $A_{i,j}$.

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You can perform operations on the matrix. In each operation, you can choose an integer $k$, then for each index $i$ ($1 \leq i \leq n$), swap $A_{i, k}$ with $A_{k, i}$. Note that cell $A_{k, k}$ remains unchanged.

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For example, for $n = 4$ and $k = 3$, this matrix will be transformed like this:

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image The operation $k = 3$ swaps the blue row with the green column.

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You can perform this operation any number of times. Find the lexicographically smallest matrix$^\dagger$ you can obtain after performing arbitrary number of operations.

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${}^\dagger$ For two matrices $A$ and $B$ of size $n \times n$, let $a_{(i-1) \cdot n + j} = A_{i,j}$ and $b_{(i-1) \cdot n + j} = B_{i,j}$. Then, the matrix $A$ is lexicographically smaller than the matrix $B$ when there exists an index $i$ ($1 \leq i \leq n^2$) such that $a_i \lt b_i$ and for all indices $j$ such that $1 \leq j \lt i$, $a_j = b_j$.

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Input

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The first line contains a single integer $t$ ($1 \leq t \leq 10^5$) — the number of test cases.

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The first line of each test case contains a single integer $n$ ($1 \leq n \leq 1000$) — the size of the matrix.

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The $i$-th line of the next $n$ lines contains $n$ integers $A_{i, 1}, A_{i, 2}, \dots, A_{i, n}$ ($1 \le A_{i, j} \le 10^9$) — description of the matrix $A$.

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It is guaranteed that the sum of $n^2$ over all test cases does not exceed $10^6$.

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Output

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For each test case, print $n$ lines with $n$ integers each — the lexicographically smallest matrix.

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Note

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Note that in every picture below the matrix is transformed in such a way that the blue rows are swapped with the green columns.

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In the first test case, we can perform $1$ operation for $k = 3$. The matrix will be transformed as below:

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image

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In the second test case, we can perform $2$ operations for $k = 1$ and $k = 3$:

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image

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image

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样例

Input #1
2
3
2 1 2
2 1 2
1 1 2
4
3 3 1 2
1 1 3 1
3 2 3 2
2 3 3 1
Output #1
2 1 1
2 1 1
2 2 2
3 1 1 2
3 1 2 1
3 3 3 3
2 3 2 1
InputCopy OutputCopy
题目信息
题号
1713E
时间限制
1 s
内存限制
256 MB
标签
2-SAT
数据结构
并查集
贪心
矩阵

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。