$ Sum Of All Submatrices Of A Given Matrix Implementation - [C++]

#1

why does this line no 8 and 9 do I cannot understand

#2

Hi @Somith
Line no 8 computes value of tl (top left) which is a formula for obtaining number of ways to choose from top-left elements while in line 9 we compute number of ways to choose from bottom-right elements that is br (bottom right).

#3

i am not getting the click in my mind on how the loops are executing ,i mean to say that what are the process that is taking place inside the loop i know it is giving for top left and bottom right

#4

See in the two for loops we are calculating the number of time an element a[i][j] can be there in a sub matrix and then just multiplying the value of a[i][j] to its occurrence. And the occurrence for each element is computed by tlbr.
Suppose we have :
1 1 1
1 1 1
1 1 1
here when you try to find out how many sub matrices will be there where a[1][1] is present then it will be 16 and also by using tlbr you will get 16 only. So tl*br is used for calculating number of matrices in which a[i][j] is present.

#5

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