Codeforces Round #257 (Div. 2) B. Jzzhu and Sequences_html/css_WEB-ITnose

B. Jzzhu and Sequences

time limit per test

1 second

memory limit per test

256 megabytes

input

standard input

output

standard output

The meaning of the question is very simple. Give three numbers x, y, n, where x =f1,y=f2 fi 1=fi-fi-1;

Find fn%(10^9 7)

a periodic function. . . . . Water passes

#include<iostream>#define M  1000000007#define N 2000000000+5using namespace std;int main(){    __int64 ans,n,x,y,i;    int a[7];    while(cin>>x>>y)    {        cin>>n;        n=n%6;            x=(x+M)%M;            y=(y+M)%M;            a[1]=x;            a[2]=y;        for(i=2;i<7;i++)        {            if(a[i<0])                a[i]=(a[i]+M)%M;            else if(i>2)                a[i]=a[i]%M;            a[i+1]=(a[i]-a[i-1])%M;        }        if(n)        cout<<a[n]<<endl;        else cout<<a[6]<<endl;    }}