UVA 1393 Highways（数学思想）

import java.util.Scanner;

public class Main{

    static int Max=305;
    static int[][] gcd=new int[Max][Max];
    static{
        for(int i=1;i<Max;++i){
            for(int j=1;j<Max;++j){
            gcd[i][j]=Gcd(i, j);
            }
        }
    }
    
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        int n,m;
        while(sc.hasNext()){
            n=sc.nextInt();
            m=sc.nextInt();
            if(n+m==0)
                break;
            System.out.println(Solve(n,m));
        }
    }

    private static int Solve(int n, int m) {
        int res=0;
        for(int i=1;i<n;++i){
            for(int j=1;j<m;++j){
                if(gcd[i][j]==1){
                int a1,a2;
                a1=(n-i)*(m-j);
                a2=Math.max(0, n-2*i)*Math.max(0, m-2*j);
                res+=a1-a2;
                //System.out.println(res);
                }
            }
        }
        return res*2;
    }

    private static int Gcd(int i, int j) {
        if(j==0)
        return i;
        else
            return Gcd(j, i%j);
    }

}