CF456B Fedya and Maths 找规律

http://codeforces.com/contest/456/problem/B

CF#260 div2 B Fedya and Maths

Codeforces Round #260

B. Fedya and Maths
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

Fedya studies in a gymnasium. Fedya's maths hometask is to calculate the following expression:

(1n + 2n + 3n + 4n) mod 5

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).

Input

The single line contains a single integer n (0 ≤ n ≤ 10105). The number doesn't contain any leading zeroes.

Output

Print the value of the expression without leading zeros.

Sample test(s)
Input
4
Output
4
Input
124356983594583453458888889
Output
0
Note

Operation x mod y means taking remainder after division x by y.

Note to the first sample:

题解：

打表找规律，发现输入是4的倍数就出4，否则出0。

而4的倍数只用看最后两位，怕了。

 1 //#pragma comment(linker, "/STACK:102400000,102400000")
 2 #include<cstdio>
 3 #include<cmath>
 4 #include<iostream>
 5 #include<cstring>
 6 #include<algorithm>
 7 #include<cmath>
 8 #include<map>
 9 #include<set>
10 #include<stack>
11 #include<queue>
12 using namespace std;
13 #define ll long long
14 #define usint unsigned int
15 #define mz(array) memset(array, 0, sizeof(array))
16 #define minf(array) memset(array, 0x3f, sizeof(array))
17 #define REP(i,n) for(i=0;i<(n);i++)
18 #define FOR(i,x,n) for(i=(x);i<=(n);i++)
19 #define RD(x) scanf("%d",&x)
20 #define RD2(x,y) scanf("%d%d",&x,&y)
21 #define RD3(x,y,z) scanf("%d%d%d",&x,&y,&z)
22 #define WN(x) printf("%d\n",x);
23 #define RE  freopen("D.in","r",stdin)
24 #define WE  freopen("1biao.out","w",stdout)
25 
26 int main() {
27     //RE;
28     ll n=0;
29     char c,prec,preprec;
30     while(scanf("%c",&c)!=EOF && c>='0' && c<='9') {
31         preprec=prec;
32         prec=c;
33         n++;
34     }
35     //printf("%c,%c,%c\n",c,prec,preprec);
36     ll t;
37     if(n>1) t=(preprec-'0')*10+(prec-'0');
38     else t=prec-'0';
39     if(t%4==0)puts("4");
40     else puts("0");
41     return 0;
42 }
View Code

 

posted @ 2014-08-09 09:05  带鱼Yuiffy  阅读(254)  评论(0)  编辑  收藏  举报