(DP) hihocoder-1239 Fibonacci

original title link:http://hihocoder.com/problemset/problem/1239

Test Instructions: for a sequence, there are several sub-sequences that form the Fibonacci sequence.

Analysis: We can dynamically add results in the process of statistics.

Since there are two 1, we need to make some distinctions, we first define m[0] to denote the number of Fibonacci numbers ending with the first 1, m[1] represents the number of Fibonacci sequences ending with the second 1, similarly, M[i] (I>1,i represents Fibonacci numbers) Represents the number of Fibonacci sequences ending with Fibonacci (i).

such as this example 1 1 2 1 2 3 4 5.

① assumes the beginning of the 1, when m[0]=1.

② then another 1, at this time because M[0]=1 already had a sequence ending with the first 1, so m[1]+=m[0], and because 1 alone can become a series, so m[0]+=1.

③ next 2, we need to see the Fibonacci number in front of him, which is the second 1, so m[2]+=m[1].

④ then is again 1, like ②, first add already have, then add own new. M[1]+=m[0],m[0]+=1.

⑤ is still 2, like ③, M[2]+=m[1].

⑥ is then 3, similar to ③⑤, M[3]+=m[2].

⑦ this time is 4, found not Fibonacci number, skip directly.

⑧ finally 5, still similar, m[4]+=m[3].

Code:

1#include <Set>2#include <map>3#include <list>4#include <cmath>5#include <queue>6#include <vector>7#include <bitset>8#include <string>9#include <cctype>Ten#include <cstdio> One#include <cstring> A#include <cstdlib> -#include <iostream> -#include <algorithm> the  - using namespacestd; -  -typedefLong Longll; +typedef unsignedLong Longull; - #defineINF (0X3F3F3F3F) + #defineLNF (0x3f3f3f3f3f3f3f3f) A #defineEPS (1E-8) at intSgnDoubleA) {returnA <-eps? -1: A < EPS?0:1;} -  - //-------------------------- -  -  - Constll mod =1000000007; in  - intfb[ -] = {1,1,2}; toll tb[ -]; +map<int,int>m; - intp; the intN; *  $ voidinit () {Panax Notoginsengm[1] =1; -m[2] =2; the      for(P =3;; p++) { +         if(Fb[p-1] + fb[p-2] >100000) Break; AFB[P] = fb[p-1] + fb[p-2]; theM[FB[P]] =p; +  -     } $ } $  -  -  the voidsolve () { - init ();Wuyi      while(~SCANF ("%d", &N)) { thememset (TB,0,sizeof(TB)); -ll ans =0; Wu         intx; -         intK =0; About          for(inti =0; I < n; i++) { $scanf"%d", &x); -  -             int*lo = Lower_bound (FB, FB +p, x); -             if(*lo! = x)Continue; A             if(x = =1) { +Ans = (ans% mod + tb[0]% MoD)%MoD; thetb[1] = (tb[1]% mod + tb[0]% MoD)%MoD; -tb[0] = (tb[0]% mod +1) %MoD; $Ans = (ans% mod +1) %MoD; the}Else { theTb[m[x]] = (tb[m[x]]% mod + tb[m[x]-1]% MoD)%MoD; theAns = (ans% mod + tb[m[x]-1]% MoD)%MoD; the             } -         } in  theprintf"%lld\n", ans); the     } About  the } the  the intMain () { +  - #ifndef Online_judge theFreopen ("1.in","R", stdin);Bayi     //freopen ("1.out", "w", stdout); the #endif the     //Iostream::sync_with_stdio (false); - solve (); -     return 0; the}

(DP) hihocoder-1239 Fibonacci