"HDOJ6217" BBP Formula (mathematical formula)

Test instructions: Given a fraction of an infinity, its sum is equal to π, and the hexadecimal representation of Pi is the number of the nth bit after the decimal point.

1≤n≤100000

Idea: From 78327614

C++double, it's annoying to write details.

1#include <cstdio>2#include <cstring>3#include <string>4#include <cmath>5#include <iostream>6#include <algorithm>7#include <map>8#include <Set>9#include <queue>Ten#include <vector> One using namespacestd; AtypedefLong Longll; -typedef unsignedint UINT; -typedef unsignedLong Longull; thetypedef pair<int,int>PII; -typedef vector<int>VI; - #defineFi first - #defineSe Second + #defineMP Make_pair - #defineN 11000 + #defineM 41 A #defineEPS 1e-8 at #definePi ACOs (-1) -  -  -  - intRead () - {  in    intv=0, f=1; -    CharC=GetChar (); to     while(c< -|| $&LT;C) {if(c=='-') f=-1; C=GetChar ();} +     while( -<=c&&c<= $) v= (v<<3) +v+v+c- -, c=GetChar (); -    returnv*F; the } *  $ ll Pow (ll a,ll b,ll MOD)Panax Notoginseng { -ll ans=1; the      while(b) +     { A         if(b&1) ans=ans*a%MOD; thea=a*a%MOD; +b>>=1; -     } $     returnans; $ } -  - DoubleBBP (intn,ll k,ll B) the { -     Doubleans=0;Wuyi      for(intI=0; i<=n;i++) ans+= (Pow ( -, N-i,8*I+B) *1.0/(8*i+b)); the      for(inti=n+1; i<=n+1001; i++) ans+= (POWF ( -, n-i)/(8*i+b)); -     returnk*ans; Wu } -  About intMain () $ { -     //freopen ("hdoj6217.in", "R", stdin); -     //freopen ("Hdoj6217.out", "w", stdout); -     intCAs; Ascanf"%d",&CAs); +      for(intv=1; v<=cas;v++) the     { -         intN; $scanf"%d",&n); then--; the         Doubleans=0.0; theANS=BBP (N,4,1) +BBP (n,-2,4) +BBP (n,-1,5) +BBP (n,-1,6); theans-=int(ans); -         if(ans<0) ans++; inans*= -; the         Charch; the         intp=int(ans); About         if(0<=p&&p<=9) ch=p+'0'; the          Else if(p==Ten) ch='A'; the          Else if(p== One) ch='B'; the          Else if(p== A) ch='C'; +          Else if(p== -) ch='D'; -          Else if(p== -) ch='E'; the          Else if(p== the) ch='F';Bayiprintf"Case #%d:%d%c\n", v,n+1, ch); the          the     } -     return 0; - } the      

"HDOJ6217" BBP Formula (mathematical formula)