POJ Round and Round We Go

Round and Round We Go
Time Limit : 2000/1000ms (Java/Other)   Memory Limit : 20000/10000K (Java/Other)
Total Submission(s) : 1   Accepted Submission(s) : 1
Problem Description
A cyclic number is an integer n digits in length which, when multiplied by any integer from 1 to n, yields a"cycle"of the digits of the original number. That is, if you consider the number after the last digit to "wrap around"back to the first digit, the sequence of digits in both numbers will be the same, though they may start at different positions.For example, the number 142857 is cyclic, as illustrated by the following table: 142857 *1 = 142857 142857 *2 = 285714 142857 *3 = 428571 142857 *4 = 571428
142857 *5 = 714285 142857 *6 = 857142
 
Input
Write a program which will determine whether or not numbers are cyclic. The input file is a list of integers from 2 to 60 digits in length. (Note that preceding zeros should not be removed, they are considered part of the number and count in determining n. Thus, "01"is a two-digit number, distinct from "1"which is a one-digit number.)
 
Output
For each input integer, write a line in the output indicating whether or not it is cyclic.
 
Sample Input
142857
142856
142858
01
0588235294117647
 
Sample Output
142857 is cyclic
142856 is not cyclic
142858 is not cyclic
01 is not cyclic
0588235294117647 is cyclic
 
Source
PKU
 
 
 

#include<iostream>

#include<cstdio>

#include<cstring>



using namespace std;



char str[100],s[100];

int len;



void Mul(int num,int a[],char s[]){

    int tmp=0,b[100];

    for(int i=0;i<len;i++)

        b[i]=a[i];

    for(int i=0;i<len;i++){

        tmp=b[i]*num+tmp;

        b[i]=tmp%10;

        tmp/=10;

        s[len-1-i]=b[i]+'0';

    }

    s[len]='\0';

    //printf("--------->  %s 
",s);

}



int isOk(char s1[],char s2[]){

    char s[200];

    strcpy(s,s1);

    strcat(s,s1);

    if(strstr(s,s2)!=NULL)      //  strstr     

        return 1;

    return 0;

}



int main(){



    //freopen("input.txt","r",stdin);



    int a[100];

    while(~scanf("%s",str)){

        len=strlen(str);

        int i,j;

        for(i=len-1,j=0;i>=0;i--)

            a[j++]=str[i]-'0';

        for(i=2;i<=len;i++){

            Mul(i,a,s);

            if(!isOk(str,s))

                break;

        }

        if(i>len)

            printf("%s is cyclic
",str);

        else

            printf("%s is not cyclic
",str);

    }

    return 0;

}