CF 390e-inna and Large Sweet Matrix (TODO)

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Test Instructions:

to a matrix of n * m, the initial element is all 0 and then a W operation.

A. Add all elements of a sub-matrix to a value of V.

B. Ask for the element of a sub-matrix and subtract the value of the 10-shaped matrix and (that is, 4 corners) of this sub-matrix four-edge extension after subtracting the entire matrix.

Ideas:

First you must read Operation B,

Is the area of green minus red, can be converted to the right large green area minus the large red area.

So the two-dimensional problem is turned into one-dimensional problem, it can be done.