Number Sequence
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 136403 Accepted Submission(s): 33062
Problem Description
A number sequence is defined as follows: f(1) = 1, f(2) = 1, f(n) = (A * f(n - 1) + B * f(n - 2)) mod 7. Given A, B, and n, you are to calculate the value of f(n).
Input
The input consists of multiple test cases. Each test case contains 3 integers A, B and n on a single line (1 <= A, B <= 1000, 1 <= n <= 100,000,000). Three zeros signal the end of input and this test case is not to be processed.
Output
For each test case, print the value of f(n) on a single line.
Sample Input
1 1 3
1 2 10
0 0 0
Sample Output
2
5
#include<stdio.h>
int main(){ __int64 a,b,n; while(scanf("%I64d%I64d%I64d",&a,&b,&n)!=EOF&&(a||b||n)) { __int64 c[105],i,k; c[1]=1;c[2]=1; for(i=3;i<100;i++) { c[i]=(a*c[i-1]+b*c[i-2])%7; if(c[i]==1&&c[i-1]==1) break; } i=i-2; k=n%i; if(k==0) printf("%I64d\n",c[i]); else printf("%I64d\n",c[k]); } return 0;}