标签：codeforces
题目链接：http://codeforces.com/problemset/problem/456/B
Fedya studies in a gymnasium. Fedya‘s maths hometask is to calculate the following expression:
for given value of n. Fedya managed to complete the task. Can you? Note that given number n can be extremely large (e.g. it can exceed any integer type of your programming language).
The single line contains a single integer n (0?≤?n?≤?10105). The number doesn‘t contain any leading zeroes.
Print the value of the expression without leading zeros.
4
4
124356983594583453458888889
0
Operation x mod y means taking remainder after division x by y.
Note to the first sample:
循环节为4；
代码如下：
#include <cstdio>
#include <cstring>
#include <cmath>
#include <iostream>
#include <algorithm>
using namespace std;
__int64 sum;
char s[1000017];
int main()
{
while(~scanf("%s",s))
{
int len = strlen(s);
int i, n;
int tt = 0;
if(len == 1)
tt = s[0]-'0';
else
{
tt = s[len-1]-'0'+(s[len-2]-'0')*10;
}
n = tt ;
if(n > 4)
{
n %= 4;
if(n == 0)
n = 4;
}
sum = 0;
int j;
for(i = 1; i <= 4; i++)
{
__int64 t = 1;
for(j = 1; j <= n;j++)
{
t*=i;
}
t%=5;
sum+=t;
}
printf("%I64d\n",sum%5);
}
return 0;
}Codeforces Round #260 (Div. 2) B. Fedya and Maths（循环节）,布布扣,bubuko.com
Codeforces Round #260 (Div. 2) B. Fedya and Maths（循环节）
标签：codeforces
原文地址：http://blog.csdn.net/u012860063/article/details/38458873
