小数高精度乘法
program P1001; Type arr=record a:array[1..10000] of longint; len:longint; xs:longint; end; Var s:ansistring; n,i,j,k,len:longint; r:arr; Procedure relax(var c:arr); var i,j:longint; begin while (c.a[c.len]=0) and (c.len>1) do dec(c.len); if (c.len=1) and (c.a[1]=0) then begin c.xs:=0; exit; end; i:=1; while (c.a[i]=0) do inc(i); dec(i); if (i>0) then begin if (c.xs>=i) then dec(c.xs,i) else begin i:=c.xs; c.xs:=0; end; for j:=i+1 to c.len do c.a[j-i]:=c.a[j]; dec(c.len,i); end; end; procedure prin(c:arr); var i:longint; begin relax(c); if (c.xs=0) then begin for i:=c.len downto 1 do write(c.a[i]); writeln; exit; end; if (c.xs<=c.len) then begin for i:=c.len downto c.xs+1 do write(c.a[i]); write('.'); for i:=c.xs downto 1 do write(c.a[i]); writeln; exit; end; write('.'); for i:=1 to c.xs-c.len do write('0'); for i:=c.len downto 1 do write(c.a[i]); writeln; end; Procedure cheng(a:arr;b:arr;var c:arr); var i,j:longint; begin fillchar(c,sizeof(c),0); for i:=1 to a.len do for j:=1 to b.len do begin inc(c.a[i+j-1],a.a[i]*b.a[j]); inc(c.a[i+j],c.a[i+j-1] div 10); c.a[i+j-1]:=c.a[i+j-1] mod 10; end; c.len:=a.len+b.len+1; c.xs:=a.xs+b.xs; relax(c); end; procedure jie(a:arr;b:longint;var c:arr); begin if (b=1) then c:=a else if (b mod 2=0) then begin jie(a,b div 2,c); cheng(c,c,c); end else begin jie(a,b div 2,c); cheng(c,c,c); cheng(c,a,c); end; end; Begin while (not(eof)) do begin readln(s); len:=length(s); i:=pos(' ',s); j:=pos('.',s); if j=0 then begin r.xs:=0; r.len:=i-1; for k:=1 to r.len do r.a[r.len-k+1]:=ord(s[k])-48; end else begin r.xs:=i-j-1; r.len:=i-2; for k:=1 to j-1 do r.a[r.len-k+1]:=ord(s[k])-48; for k:=j+1 to i-1 do r.a[r.len-k+2]:=ord(s[k])-48; end; relax(r); i:=len; while (s[i]<>' ') do dec(i); n:=0; for k:=i+1 to len do n:=n*10+ord(s[k])-48; jie(r,n,r); prin(r); end; end.