codeup26756 bit number problem

codeup26756 bit number problem

Time limit 1000MS/128MB
The title describes How many of the numbers in the N-digit number have an even number 3.  Since the result can be very large, you only need to output this answer to 12345 of the value of the remainder. input read into a number n output

The number of outputs has an even number of numbers 3. Sample Input

2

Sample output

73

hint 1<=n<=1000

Code

#include <iostream>
using namespace std;
const int N = 1005;
int a[n][2];

int main () {
	int n,k=9;
	cin>>n;
	a[1][0]=9; A[1][1]=1;
	A[I][0] I-digit an even number of 3    a[i][1] I in the number of odd number 3 for
	(int i=2; i<=n; i++) {
		if (i==n) k--;	The first digit cannot be 0 
		a[i][0]= (k*a[i-1][0]+a[i-1][1])%12345;
		A[i][1]= (a[i-1][0]+k*a[i-1][1])%12345;
	}
	cout<<a[n][0]<<endl;
	return 0;
}