Any Hint for Fibo Sum?

#1

Hi,

I am able to calculate the Fibonacci sum of {0 - N } numbers. I cannot able to proceed further, How to calculate in Range of Fibonacci numbers.

Please check the code.

Thanks,
Pardeep Sharma.

#2

Just do fib(M+2) - fib(N+1)

#3

Hi,

This method : fib(M+2) - fib(N+1) didn’t help.

To generate 0 to N Fibonacci numbers, I have taken F1 and T matrix as :

long[] F1 = {0, 1, 1};
long T[][] = new long[][]{{0, 1, 0}, {1, 1, 0}, {1, 1, 1}};

It works for 0-3 & 0-5 individually but for Range like 3-5, it fails :frowning:

Please check or suggest if I am generating wrong matrix T.

Thanks.

#4

How did you come up with this

long[] F1 = {0, 1, 1};
long T[][] = new long[][]{{0, 1, 0}, {1, 1, 0}, {1, 1, 1}};
#5

long[] Fi or F1 = { f(0) , f(1), f(0) + f(1) }

long T[][] = new long[][]{{0, 1, 0}, {1, 1, 0}, {1, 1, 1}};

T . Fi = F i+1

Therefore F i+1 = { f(1), f(2), f(0) + f(1) + f(2) }

So,

F(n) = T ^ n . F1

This helps to generate sum of N fibonacci numbers.

#6

Why don’t you use F(n+2) - 1 for getting sum directly ?

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#8

Hi,

I’d some modification and able to pass example test cases in question.

But during submission, i can able to pass just one test case. I handled modulo operation too.

Please check.

Thanks

#9

As I explained earlier, resultM - resultN can be negative. So just do
(resultM - resultN)+MOD)%MOD.

1 Like