#P0136. Sakurako and Water
Sakurako and Water
Problem
During her journey with Kosuke, Sakurako and Kosuke found a valley that can be represented as a matrix of size , where at the intersection of the row and the column is a mountain with a height of . If , then there is a lake there.
Kosuke is very afraid of water, so Sakurako needs to help him:
- With her magic, she can select a square area of mountains and increase the height of each mountain on the main diagonal of that area by exactly one.
More formally, she can choose a submatrix with the upper left corner located at and the lower right corner at , such that . She can then add one to each element at the intersection of the row and the -th column, for all k such that .
Determine the minimum number of times Sakurako must use her magic so that there are no lakes.
Input
The first line contains a single integer — the number of test cases.
Each test case is described as follows:
- The first line of each test case consists of a single number .
- Each of the following n lines consists of n integers separated by spaces, which correspond to the heights of the mountains in the valley .
Output
For each test case, output the minimum number of times Sakurako will have to use her magic so that all lakes disappear.
Example : in
4
1
1
2
-1 2
3 0
3
1 2 3
-2 1 -1
0 0 -1
5
1 1 -1 -1 3
-3 1 4 4 -4
-1 -1 3 0 -5
4 5 3 -3 -1
3 1 -3 -1 5
Example : out
0
1
4
19
相关
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