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10229 :WA.....I am angry now !!!
Posted: Fri Jun 30, 2006 8:15 pm
by akdwivedi
Hi !! here is my code , I am getting wrong answer ..can anybody help me.......
what is wrong ??
#include<iostream>
#include<cstdio>
#include<math.h>
using namespace std;
long long int Fib(long long int n)
{
long long int i=1,h=1;
long long int j =0,k=0,t;
while (n > 0) {
if (n%2 == 1) {
t = j*h;
j = i*h + j*k + t;
i = i*k + t;
}
t = h*h;
h = 2*k*h + t;
k = k*k + t;
n=(int)floor(n/2.0);
}
return j;
}
int main()
{
long long int n,m;
while(scanf("%lld%lld",&n,&m)!=EOF)
{
printf("%lld\n",Fib(n)%((int)pow(2,m)));
}
return 0;
}
even this algo is work on O(lon(n));;;;.....reaply.. soon
thanks..
Posted: Fri Jun 30, 2006 8:37 pm
by 898989
Salamo Aleko
You can visit steven halim site for uva problem solving
And find the implemenation in his explantation
I used it and get ac in 10 minutes.
Sorry i do not know a reference. If you got a link..give it to us.
Posted: Tue Dec 05, 2006 11:48 am
by joy
I got WA.....
plz give me some input/ output.....
here is my code:
plz help..........
Posted: Sat Dec 09, 2006 7:50 am
by Jan
Check the samples...
Input:
Output:
Hope these help.
Posted: Fri Dec 22, 2006 7:14 pm
by joy
thanks Jane
...
I got ACC now
Posted: Fri Jan 26, 2007 12:17 am
by jojo
Hi
Could anyone tell me how to solve tihs problem ?
I've got our Fn by using O(lg) algorithm and I know that
(a*b*c)%n==((a%n)*(b%n)*(c%n))%n
but I don't know how to use it?
Should I find prime factors of this number and use them to calculate Fn%m - I think that 2147483647th fibbonacii is too big for doing this .
I'm confused.
plx help me
jojo
Posted: Fri Jan 26, 2007 2:26 pm
by joy
jojo wrote:Hi
Could anyone tell me how to solve tihs problem ?
I've got our Fn by using O(lg) algorithm and I know that
(a*b*c)%n==((a%n)*(b%n)*(c%n))%n
but I don't know how to use it?
Should I find prime factors of this number and use them to calculate Fn%m - I think that 2147483647th fibbonacii is too big for doing this .
I'm confused.
plx help me
jojo
hi,
Code: Select all
Sequence of Fibonacci numbers:
Fibo(i) : 1 1 2 3 5 8 13 21 34 55 89 144 233...
Sequence of Fibonacci numbers mod 2:
Fibo(i)%2 : 1 1 0 1 1 0 1 1 0...
Sequence of Fibonacci numbers mod 3:
Fibo(i)%3 : 1 1 2 0 2 2 1 0 1 1 2 0...
You dont need to use n time loop to solve this problem
Hope it helps..
10229 runtime error
Posted: Wed May 16, 2007 6:13 pm
by code_man
I have runtime error, but I don't know why? Somebody can tell me what's wrong with this code? :
Code: Select all
#include<iostream>
using namespace std;
int fibon(int a);
int potega(int b);
int main()
{
int n, m;
while(cin>>n>>m)
{ cout<<fibon(n)%potega(m)<<"\n"; }
}
/*****************************************************/
int fibon(int a)
{
if(a==0) return 0;
if(a<1) return 1;
else
return (fibon(a-1)+ fibon(a-2));
}
int potega(int b)
{
int pomoc=1;
for(int i=0; i<b; i++)
{ pomoc*=2; }
return pomoc;
}
Posted: Sun Jul 22, 2007 12:55 pm
by newton
i cant find the point like jojo.
may you help explaining it elaborately....
thanx
Posted: Sun Jul 22, 2007 1:05 pm
by mf
Read previous posts in this thread.
Posted: Sat Sep 08, 2007 5:00 am
by ifox
yes, long long will get ac
wyvmak wrote:at a rough scan on your code, what i think is, there seems not a need to use long double, you can make it to int, or long long. then, your program may be better, at least need not worry about floating point error. though i cannot tell you whether it will get AC
Re: 10229 - Modular Fibonacci
Posted: Sat May 31, 2008 4:09 pm
by fR0D
can somebody please point out why am i getting WA?
Code: Select all
#include<iostream>
using namespace std;
long long p;
long long pow(int i,int j)
{
long long val=1;
int k;
for (k=1;k<=j;k++)
val=val*i;
return val;
}
long long conquer_fibonacci(long long n)
{
long long i,h,j,k,t;
i=h=1;
j=k=0;
while(n>0)
{
if(n%2==1)
{
t=j*h;
j=((i*h)%p + (j*k)%p +t%p)%p;
i=i*k + t;
}
t=h*h;
h=2*k*h + t;
k=k*k + t;
n=(long long) n/2;
}
return j;
}
int main()
{
long long n,res,m;
while(scanf("%lld%lld",&n,&m)!=EOF)
{
p=pow(2,m);
res=conquer_fibonacci(n);
printf("%lld\n",res%pow(2,m));
}
return 0;
}
Re: 10229 - Modular Fibonacci
Posted: Sat May 31, 2008 4:43 pm
by helloneo
fR0D wrote:can somebody please point out why am i getting WA?
Sometimes k and t can be very big.. so it may cause overflow error..
Re: 10229 - Modular Fibonacci
Posted: Sat May 31, 2008 9:08 pm
by fR0D
so how can i avoid that???
10229 - Modular Fibonacci --> here more case testing
Posted: Wed Aug 13, 2008 1:36 am
by carliros
Input
11 7
11 6
2147483647 2
0 0
2147483647 0
2147483647 19
output
89
25
1
0
0
325917