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FIBOSUM - Fibonacci Sum |
The Fibonacci sequence is defined by the following relation:
- F(0) = 0
- F(1) = 1
- F(N) = F(N - 1) + F(N - 2), N >= 2
Your task is very simple. Given two non-negative integers N and M, you have to calculate the sum (F(N) + F(N + 1) + ... + F(M)) mod 1000000007.
Input
The first line contains an integer T (the number of test cases). Then, T lines follow. Each test case consists of a single line with two non-negative integers N and M.
Output
For each test case you have to output a single line containing the answer for the task.
Example
Input: 3 0 3 3 5 10 19 Output: 4 10 10857
Constraints
- T <= 1000
- 0 <= N <= M <= 109
Added by: | David Gómez |
Date: | 2010-12-04 |
Time limit: | 1s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: ASM64 |
Resource: | My Own |
hide comments
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2015-06-03 13:26:13 Aman Agarwal
AC in one go.. learned a new way to calculate fibonacci series and fibonacci sum |
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2015-05-21 13:34:16 kartikay singh
NEGATIVE MODULUS COST ME 2WA FINAlly AC :D |
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2015-04-22 21:10:20 karan
nice problem ^_^ |
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2015-04-17 08:41:39 Prasanna Patil
When i was using modulo only at answer(final ans) time got TLE. After that optimized it and used modulo whenever wherever possible. (Got AC in 0.00). Well learned hell lot of things. |
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2015-04-03 20:07:19 reddragon
finally acc |
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2015-03-17 11:05:35 xxbloodysantaxx
Try taking out a recurrence for S(n) rather than expressing the sum in fibbonaci term.... Will make you feel better surely :) |
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2015-02-03 20:52:39 Yash
My 60th :) Use long datatype...int cost me WAs |
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2015-01-29 19:45:53 abhijeet gusain
log(n) + be careful of the negative mod.. :) |
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2015-01-27 17:21:19 AYUSH SAHU
finally accepted....:) |
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2015-01-24 19:46:50 Abhinandan Agarwal
accepted in 0.00 secs B-) |