问题描述
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).
MEMORY LIMIT EXCEEDED CODE
#include <iostream>
using namespace std;
int m(int A, int B, int n) {
if (n == 1 || n == 2) return 1;
else {
return (A * m(A, B, n-1) + B * m(A, B, n - 2)) % 7;
}
}
int main()
{
int A, B, n;
while (cin >> A >> B >> n) {
if (A == 0 && B == 0 && n == 0) break;
cout << m(A, B, n) << endl;
}
return 0;
}
AC CODE
#include<iostream>
using namespace std;
int f(int A, int B,int n)
{
if(n==1 || n==2)
return 1;
else
return (A*f(A,B,n-1)+B*f(A,B,n-2))%7;
}
int main()
{
int a,b,n;
while(cin>>a>>b>>n,a||b||n)
{
cout<<f(a,b,n%49)<<endl;
}
return 1;
}
上述代码,当输入的n mod 49 = 0时陷入死循环,这样也能AC?