zoj 2105 Number Sequence

#include <stdio.h>#include <stdlib.h>#include <iostream>using namespace std;int num[50];void compute(int a,int b,int n){int i,m;for(i=3; i<=49; i++){num[i] = (a*num[i-1] + b*num[i-2]) % 7;if( num[i] == 1 && num[i-1] == 1 )break;}        m = i-2;    cout << num[(n-1)%m+1] << endl;}int main(void){int a,b,n;num[1] = 1;num[2] = 1;while( cin >> a >> b >> n ){if( !(a||b||n) )break;compute(a,b,n);}return 0;}