cf#257(Div.2) B. Jzzhu and Sequences_html/css_WEB-ITnose
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output
Jzzhu has invented a kind of sequences, they meet the following property:
You are given x and y, please calculate fn modulo 1000000007 (109?+?7).
Input
The first line contains two integers x and y (|x|,?|y|?≤?109). The second line contains a single integer n (1?≤?n?≤?2·109).
Output
Output a single integer representing fn modulo 1000000007 (109?+?7).
Sample test(s)
input
2 33
output
input
0 -12
output
1000000006
Note
In the first sample, f2?=?f1?+?f3, 3?=?2?+?f3, f3?=?1.
In the second sample, f2?=??-?1; ?-?1 modulo (109?+?7) equals (109?+?6).
题意:给你一个递推式,f2=f1+f3-->变形为:f[i]=f[i-1]-f[i-2];输入f[1]和f[2];求第n个数的值;如果你想打表的话劝你放弃吧!肯定会超时的,还记得高中的等差序列吗!对这绝对是一个周期序列!而且周期为6;
#includeint main(){ __int64 a[10],x,y,n; int i; scanf("%I64d%I64d",&x,&y); a[1]=x;a[2]=y; for(i=3;i
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