H. Theater Square(简单数学)——东二

题目：http://codeforces.com/gym/101911/problem/H

见图，即可轻松想出

#include
using namespace std;

int main()
{
    int n,m;
    scanf("%d%d",&n,&m);
    int x1,y1,x2,y2;
    scanf("%d%d%d%d",&x1,&y1,&x2,&y2);
    bool sqr1=0,sqr2=0,sqr3=0;
    ///sqr1,2分别是有喷泉的两侧,sqr3是没喷泉的行
    if((y1-1)%2!=0) sqr1 = 1;
    if((m-y2)%2!=0) sqr2 = 1;
    if(m%2!=0) sqr3 = 1;
    int ans = (sqr1 + sqr2) * (x2 - x1 + 1) + sqr3 * (n - (x2 - x1 + 1));
    printf("%d\n",(ans+1)/2);
    return 0;
}