標籤:style http color os io 資料 for ar
Fedya studies in a gymnasium. Fedya‘s maths hometask is to calculate the following expression:
(1
n?+?2
n?+?3
n?+?4
n)
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:
不懂什麼費馬小定理。打表之後發現:n%4=0的時候輸出4,
其餘輸出0,但n資料太大了.我們知道:100以上的數可以分解成100*x+y者只需考慮y就可以了,即只需考慮最後兩位。這就好辦了。讀入字串得到最後兩位模數就可以了
#include<iostream>#include<cstdio>#include<cstring>#include<algorithm>#include<limits.h>#include<cmath>using namespace std;const int maxn=1e6;char s[maxn];int main(){ while(~scanf("%s",s)) { int len=strlen(s); int sum=0; sum+=s[len-1]-'0'+(s[len-2]-'0')*10; if(sum%4==0) cout<<4<<endl; else cout<<0<<endl; } return 0;}