PKU2413 how many fibs

       學以致用，高精度題目一個！先用高精度加法預處理，接着一起二分搜索。

program fibs; const maxlen=200; maxn=500; stop='0 0'; type hightype=record num:array[0..maxlen] of longint; len:longint; end; var fib:array[0..maxn] of hightype; limit,a,b:hightype; tot,left,right:longint; str,sa,sb:string; procedure highin(st:string; var x:hightype); var i:longint; begin x.len:=length(st); fillchar(x.num,sizeof(x.num),0); for i:=x.len downto 1 do x.num[x.len+1-i]:=ord(st[i])-ord('0'); end; function compare(a,b:hightype):longint; var i:longint; begin if a.len>b.len then exit(1); if a.len<b.len then exit(-1); for i:=a.len downto 1 do if a.num[i]>b.num[i] then exit(1) else if a.num[i]<b.num[i] then exit(-1); exit(0); end; function getmax(a,b:longint):longint; begin if a>b then exit(a); exit(b); end; procedure highplus(a,b:hightype; var c:hightype); var i:longint; begin c.len:=getmax(a.len,b.len); fillchar(c.num,sizeof(c.num),0); for i:=1 to c.len do c.num[i]:=a.num[i]+b.num[i]; for i:=1 to c.len do if c.num[i]>=10 then begin dec(c.num[i],10); inc(c.num[i+1]); end; while c.num[c.len+1]>0 do inc(c.len); end; procedure prework; var i:longint; begin limit.len:=101; fillchar(limit.num,sizeof(limit.num),0); limit.num[101]:=1; fib[0].len:=1; fillchar(fib[0].num,sizeof(fib[0].num),0); fib[0].num[1]:=0; fib[1].len:=1; fillchar(fib[1].num,sizeof(fib[1].num),0); fib[1].num[1]:=1; fib[2].len:=1; fillchar(fib[2].num,sizeof(fib[2].num),0); fib[2].num[1]:=2; for i:=3 to maxn do begin highplus(fib[i-2],fib[i-1],fib[i]); if compare(fib[i],limit)>0 then begin tot:=i; exit; end; end; end; procedure doit(str:string); var x:longint; begin x:=pos(' ',str); sa:=copy(str,1,x-1); sb:=copy(str,x+1,length(str)-x); end; function binarysmall(x:hightype):longint; var mid,left,right,key:longint; begin left:=0; right:=tot; while left<right-1 do begin mid:=(left+right) shr 1; key:=compare(fib[mid],x); if key>=0 then right:=mid else left:=mid; end; exit(left); end; function binarynobig(x:hightype):longint; var mid,left,right,key:longint; begin left:=0; right:=tot; while left<right-1 do begin mid:=(left+right) shr 1; key:=compare(fib[mid],x); if key=0 then exit(mid) else if key>0 then right:=mid else left:=mid; end; exit(left); end; procedure outit; begin writeln(right-left); end; procedure bigmain; begin readln(str); while str<>stop do begin doit(str); highin(sa,a); highin(sb,b); left:=binarysmall(a); right:=binarynobig(b); outit; readln(str); end; end; begin assign(input,'a.in'); reset(input); assign(output,'a.out'); rewrite(output); prework; bigmain; close(input); close(output); end.