【BZOJ】【P2659】【Beijing wc2012】【算不出的算式】【题解】【打表】

传送门:http://www.lydsy.com/JudgeOnline/problem.php?id=2659

打表找规律

Code:

#include<iostream>
using namespace std;
typedef long long LL;
LL p,q,ans;
int main(){
	cin>>p>>q;
	if(p<q)swap(p,q);
	if(p==q){cout<<(1+(p-1)/2)*(p-1)/2<<endl;return 0;}
	cout<<(p-1)*(q-1)/4<<endl;
	return 0;
}