CodeforcesRound#257(Div.2)B.JzzhuandSequences_html/css_WEB-ITnose

time limit per test

memory limit per test

input

output

题目意思很简单 给出三个数x，y，n，其中x=f1,y=f2 fi+1=fi-fi-1;

求出fn%(10^9+7)

一个周期函数。。。。。水过

#include#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<