Codeforces 630L-L. Cracking the Code【整数快速幂】
L. Cracking the Code
time limit per test
0.5 seconds
memory limit per test
64 megabytes
input
standard input
output
standard output
The protection of a popular program developed by one of IT City companies is organized the following way. After installation it outputs a random five digit number which should be sent in SMS to a particular phone number. In response an SMS activation code arrives.
A young hacker Vasya disassembled the program and found the algorithm that transforms the shown number into the activation code.Note: it is clear that Vasya is a law-abiding hacker, and made it for a noble purpose — to show the developer the imperfection of their protection.
The found algorithm looks the following way. At first the digits of the number are shuffled in the following order
Vasya is going to write a keygen program implementing this algorithm. Can you do the same?
Input
The only line of the input contains a positive integer five digit number for which the activation code should be found.
Output
Output exactly 5 digits without spaces between them — the found activation code of the program.
Examples
input
12345
output
71232
解题思路:
将输入的n(abcde)转化成acedb后,取五次幂后五位。数据坑10000,结果是00000.
#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
long long mod(int a,int b,int m)
{
long long ans=1,i;
for(i=1;i<=b;i++)
{
ans=ans*a%m;
}
return ans;
}
int main()
{
int a,b,c,d,e;
scanf("%1d%1d%1d%1d%1d",&a,&b,&c,&d,&e);
int num=a*10000+c*1000+e*100+d*10+b;
int wc=(int)mod(num,5,100000);
//printf("%d\n",wc);
int aa,bb,cc,dd,ee;
aa=bb=cc=dd=ee=0;
aa=wc/10000;
wc=wc%10000;
bb=wc/1000;
wc=wc%1000;
cc=wc/100;
wc=wc%100;
dd=wc/10;
wc=wc%10;
ee=wc;
printf("%d%d%d%d%d",aa,bb,cc,dd,ee);
return 0;
}
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