Обсуждение @ 1133. Последовательность Фибоначчи @ Timus Online Judge

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To all who WA many times but don't know what's wrong Ural_Huang Shang 3 апр 2003 20:45

You must use 'Longint' type in the sequence,
But 'Extended' in the coefficient!

Hope this will be helpful.
Good luck.

I don't think you are right.Seen my program Ural_Banyan Tree 7 апр 2003 18:08

program t1133;
var a1,a2,i1,j1,n,j,i,t1:longint;
    b,x1,y1,t:extended;
    f:array[0..2000]of extended;
    a:array[-2000..2000]of extended;
begin
     readln(i1,x1,j1,y1,n);
     if i1>j1 then begin t1:=i1; i1:=j1; j1:=t1; t:=x1; x1:=y1;
y1:=t; end;
     f[1]:=1; f[2]:=1;
     for i:=3 to j1-i1 do f[i]:=f[i-1]+f[i-2];
     b:=trunc((y1-x1*f[j1-i1-1])/(f[j1-i1]));
     a[i1]:=x1; a[i1+1]:=b;
     if n>i1 then
        for i:=i1+2 to n do
            a[i]:=a[i-1]+a[i-2];
     if n<i1 then
        for i:=i1-1 downto n do
            a[i]:=a[i+2]-a[i+1];
     writeln(a[n]:0:0);
end.

I'm right! Ural_Huang Shang 8 апр 2003 18:56

> program t1133;
> var a1,a2,i1,j1,n,j,i,t1:longint;
>     b,x1,y1,t:extended;
>     f:array[0..2000]of extended;
>     a:array[-2000..2000]of extended;
> begin
>      readln(i1,x1,j1,y1,n);
>      if i1>j1 then begin t1:=i1; i1:=j1; j1:=t1; t:=x1; x1:=y1;
> y1:=t; end;
>      f[1]:=1; f[2]:=1;
>      for i:=3 to j1-i1 do f[i]:=f[i-1]+f[i-2];
>      b:=trunc((y1-x1*f[j1-i1-1])/(f[j1-i1])); (*)
>      a[i1]:=x1; a[i1+1]:=b;
>      if n>i1 then
>         for i:=i1+2 to n do
>             a[i]:=a[i-1]+a[i-2];
>      if n<i1 then
>         for i:=i1-1 downto n do
>             a[i]:=a[i+2]-a[i+1];
>      writeln(a[n]:0:0);
> end.
>
Pay attention that you use 'trunc' in your program (the line
with '*').It is the same as use 'Longint'.

Re: I'm right! Ural_Banyan Tree 15 апр 2003 11:51

f:array[0..2000]of extended;
Pay attention that this must use 'extended';
Do you understand??

Re: I'm right! Ural_Huang Shang 18 апр 2003 19:18

No, it doesn't need to be. Just use Longint, that's OK!

Re: I'm right! Ural_Huang Shang 18 апр 2003 19:24

In array F, you must use 'Extended', but in array A, you MUST
use 'Longint'. In my first saying I meant this!

Re: I'm right! Stupnikov Pavel 31 мар 2004 21:31

Try to use trunc (((y1-x1*f[j1-i1-1])/(f[j1-i1]))+1e-6).

Whats Wrong? WA10 Uran 22 мар 2007 23:02

#include <iostream.h>
#include <iostream>
long p(long q)
{return (q+1000);}
int main()
{
    #ifndef ONLINE_JUDGE
    freopen("input.txt", "rt", stdin);
    freopen("output.txt", "wt", stdout);
    #endif
    long double a[2002];
    long double c[2002];
    long double x[2002];
    long i,j,n,t;
    for (t=0;t<2002;t++){a[t]=c[t]=x[t]=0;}
    cin>>i;
    cin>>a[p(i)];
    cin>>j;
    cin>>a[p(j)]>>n;
    if (i>j)
    {
    t=i;
    i=j;
    j=t;
    }//i<j
    c[p(i)]=1;x[p(i)]=0;
    c[p(i+1)]=0;x[p(i+1)]=1;
    for (t=i+2;t<j+1;t++){c[p(t)]=c[p(t-1)]+c[p(t-2)];x[p(t)]=x[p(t-1)]+x[p(t-2)];}
    a[p(i+1)]=a[p(j)]/x[p(j)]-c[p(j)]/x[p(j)]*a[p(i)];
    if (i<=n)
    {
        for (t=i+2;t<n+1;t++)
        {a[p(t)]=a[p(t-1)]+a[p(t-2)];}
    }
    if (i>n)
    {
        for (t=i-1;t>n-1;t--){a[p(t)]=a[p(t+2)]-a[p(t+1)];}
    }
    cout<<(long)a[p(n)];
    return 0;
}

No subject cpc 10 ноя 2007 16:42

Edited by author 10.11.2007 16:47

Re: To all who WA many times but don't know what's wrong Ural_Li Zhi 23 авг 2003 06:46

Oh!
No wonder I always got wrong answer!

Re: I'm right! partisan (Andrey Korotkov) 10 ноя 2007 16:14

Use round! When integers will be <0, trunc(-1+1e-6) will be equals to 0!

Edited by author 10.11.2007 16:44

Обсуждение задачи 1133. Последовательность Фибоначчи