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I really need help to solve the following: T(n)=T(n-a)+n where a is a constant greather or equal 1.
So I started to iterate T(n)=T(n-a)+n =T(((n-a)+n)-a)+n =T(3n-3a)+n =T(((3n-3a)+n)-a)+n =T(4n-4a)+n
this brings me to the Basic: T(kn-ka)+n.
Is it right ? I am not sure how to solve such Terms with a constant ? thank you for your help !!