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FIBOSUMT - Fibonacci extraction Sum |
Some people may found FIBOSUM a too easy problem. We propose here a useful variation.
Fib is the Fibonacci sequence: For any positive integer i: if i<2 Fib(i) = i, else Fib(i) = Fib(i-1) + Fib(i-2)
Input
The first line of input contains an integer T, the number of test cases. On each of the next T lines, your are given tree integers c, k, N.
Output
Print Sum(Fib(ki+c) for i in [1..N]). As the answer could not fit in a 64-bit container, just output your answer modulo 1000000007.
Example
Input: 1 3 5 2
Output: 254
Explanations
Index-1 Fib sequence : 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, ... We want the 5*1+3 = 8th and 5*2+3 = 13th ones, thus the answer is 21 + 233 = 254.
Constraints
0 < T <= 60606 0 <= c < k <= 2^15 0 < N <= 10^18
The numbers c,k,N are uniform randomly chosen in their range. For your information, constraints allow 1.3kB of Python3 code to get AC in 0.30s, it could be hard. A fast C-code can get AC around 0.01s. (Timing edited 2017-02-11, after compiler changes) Warning: Here is Cube cluster, you can try the classical edition (clone with Pyramid cluster). Have fun ;-)
Added by: | Francky |
Date: | 2014-04-06 |
Time limit: | 10s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: ASM64 |
Resource: | Own Problem |
hide comments
2015-08-06 11:52:57
could k*n+c >10^18? =(Francky)=> (k*N+c)_max is 10^18 + 2^30, that is very near in proportion to 10^18, it could be higher, but in fact no in the input file. Last edit: 2015-08-06 17:59:49 |
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2014-05-17 16:53:02 [Lakshman]
@Francky any suggestion why I am getting WA. Thanks. --ans(Francky)--> What is the range of your brute force checker ? --Lakshman-> Actually I have checked form many n = 2000000016 +/-1000 and n <= 1000 and randomly chosen c and k. --ans(Francky)--> Then take a look again at your brute force, because you fail very soon. 2 < c,k,n < 4. Last edit: 2014-05-17 17:55:51 |
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2014-04-08 21:59:48 (Tjandra Satria Gunawan)(曾毅昆)
Thank you for tutorial edition :) |