Position in Fraction
You have a fraction . You need to find the first occurrence of digit c into decimal notation of the fraction after decimal point.
Input
The first contains three single positive integers a, b, c (1 ≤ a < b ≤ 105, 0 ≤ c ≤ 9).
OutputPrint position of the first occurrence of digit c into the fraction. Positions are numbered from 1 after decimal point. It there is no such position, print -1.
Examples1 2 0
2
2 3 7
-1
The fraction in the first example has the following decimal notation: . The first zero stands on second position.
The fraction in the second example has the following decimal notation: . There is no digit 7 in decimal notation of the fraction.
code:
#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
int main(){
int n,m,c,i;
scanf("%d%d%d",&m,&n,&c);
int pos = -1;
int fz = m,fm = n;
i = 0;
while(1){
i++;
fz *= 10;
if(fz / fm == c){
pos = i;
break;
}
fz = fz % fm;
if(i >= 100005) break;//限制循环节长度
}
printf("%d\n",pos);
return 0;
}
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