hdu 1005

Number Sequence

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 46877    Accepted Submission(s): 10365

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 31 2 100 0 0

 

Sample Output

25

 

#include<iostream>

using namespace std;

int main()

{

int a,b,n,c[50]; 

 while(cin>>a>>b>>n,a||b||n)

 { 

 c[0]=1;

c[1]=1;

for( int i = 2; i < 50; i++) 

 { 

 c[i]=(a*c[i-1]+b*c[i-2])%7;

}

if(n%49==0)

{ 

 cout<<c[48]<<endl; 

 }

else

{ 

 cout<<c[n%49-1]<<endl;

 }

 }

return 0;

}

#include <iostream>

using namespace std;

int main()

{

int A,B,fn,fn1,fn2,i,map[49];

int n; 

 while(cin>>A>>B>>n)

{

if(n==0&&B==n&&A==B) break;

map[0]=1;

map[1]=1;

for(i=2;i<=48;i++)

{ 

 map[i]=(A*map[i-1]+B*map[i-2])%7;

 }

if(n%49==0) 

cout<<map[48]<<endl; 

 else

{ 

 cout<<map[n%49-1]<<endl;

}

 }

return 0;

 }