Buildings

2 3 2 2
3 3 1 1

1
2

Hint
Case 1 :

You can split the floor into five  apartments. The answer is 1.

Case 2:

You can split the floor into three  apartments and two  apartments. The answer is 2.


If you want to split the floor into eight  apartments, it will be unacceptable because the apartment located on (2,2) can‘t have windows.
 

須要註意特判一中情況。即不合法塊在正中間的時候，並不造成影響。

#include <iostream>
#include <cstring>
#include <cstdlib>
#include <cstdio>
#include <algorithm>
using namespace std;
int n, m, x, y;
int main()
{
    while(scanf("%d%d%d%d", &n, &m, &x, &y)!=EOF)
    {
        if(n == m && (n % 2 == 1 && m % 2 == 1) && (x == y && x == (n+1)/2))
        {
            cout << (n -1) / 2 << endl;
            continue;
        }
        int Min = min(n, m); int ans;
        if(Min & 1) ans = (Min + 1) / 2;
        else ans = Min / 2;
        int res = -10;
        int xx = x - 1, yy = y;
        if(xx >= 1 && yy >= 1) res = max(res, min(xx-1,min(yy-1,m-yy)));
        xx = x, yy = y-1;
        if(xx >= 1 && yy >= 1) res = max(res, min(min(xx-1,n-xx),yy-1));
        xx = x + 1, yy = y;
        if(xx <=n && yy >= 1) res = max(res, min(n-xx,min(yy-1,m-yy)));
         xx = x, yy = y+1;
        if(xx >= 1 && yy <= m) res = max(res, min(min(xx-1,n-xx),m-yy));
        res += 1;
        ans = max(ans, res);
        printf("%d\n", ans);
    }
    return 0;
}