急一个小小的c程序请教……
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.
#include <stdio.h>
int main()
{
int A,B,n,i,f1=1,f2=1,f3;
while(scanf("%d %d %d",&A,&B,&n)!=EOF);
{
for(i=1;i <=n;i++)
{
if(i==1 ? ?i==2)
f3=1;
else
f3=(A*f2+B*f1)%7;
f1=f2;f2=f3;
}
printf("%d\n",f3);
}
}
要怎么改才正确呢?