Manthan, Codefest 19 (open for everyone, rated, Div. 1 + Div. 2)
C
Magic Grid
Codeforces
1800
原题
← BD →
翻译中…

Let us define a magic grid to be a square matrix of integers of size $n \times n$, satisfying the following conditions.

翻译中…
  • All integers from $0$ to $(n^2 - 1)$ inclusive appear in the matrix exactly once.
  • Bitwise XOR of all elements in a row or a column must be the same for each row and column.
翻译中…

You are given an integer $n$ which is a multiple of $4$. Construct a magic grid of size $n \times n$.

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Input

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The only line of input contains an integer $n$ ($4 \leq n \leq 1000$). It is guaranteed that $n$ is a multiple of $4$.

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Output

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Print a magic grid, i.e. $n$ lines, the $i$-th of which contains $n$ space-separated integers, representing the $i$-th row of the grid.

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If there are multiple answers, print any. We can show that an answer always exists.

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Note

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In the first example, XOR of each row and each column is $13$.

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In the second example, XOR of each row and each column is $60$.

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样例

Input #1
4
Output #1
8 9 1 13
3 12 7 5
0 2 4 11
6 10 15 14
InputCopy OutputCopy
Input #2
8
Output #2
19 55 11 39 32 36 4 52
51 7 35 31 12 48 28 20
43 23 59 15 0 8 16 44
3 47 27 63 24 40 60 56
34 38 6 54 17 53 9 37
14 50 30 22 49 5 33 29
2 10 18 46 41 21 57 13
26 42 62 58 1 45 25 61
InputCopy OutputCopy
题目信息
题号
1208C
时间限制
1 s
内存限制
256 MB
标签
构造

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