Advanced backtracking webinar

#1

why [r-c+n-1] for left diagonal and [r+c] for right diagonal??

#2

@Ambuj-Singh-514796906079795 please tell the time stamp where this is mentioned

#3

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#4

please check at 31:19

#5

@Ambuj-Singh-514796906079795
Each diagonal follows a certain property.
The main diagonal (from top left to bottom right) has indices such the difference between r and c for its coordinates (r,c) is constant across the diagonal.
Since we are taking the difference, it could go negative though. Hence to ensure that negative differences do not create a problem while indexing, we add a constant number i.e. n-1 to it to make it positive.
This is not needed while indexing the cells of the other elements. Hence r+c is sufficient for the other diagonal.

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#6

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