uva 11231

From Evernote:

11231

有人想要塞棋盤在畫裡面
看能塞幾個

無想法，ad hoc
GOOGLE完發現
長跟列各-7相乘在除2
如果是偶數，看右下角是不是白色的，是的話+1不是不用加

[sourcecode language="cpp"]
//============================================================================
// Name : Black and white painting.cpp
// Date : 2013 2013/1/27 下午9:41:09
// Author : GCA
//============================================================================
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <climits>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <cctype>
#include <utility>
using namespace std;
typedef long long ll;
typedef unsigned int uint;
#define Set(a,s) memset(a,s,sizeof(a))
#define Write(w) freopen(w,"w",stdout)
#define Read(r) freopen(r,"r",stdin)
#define Pln() printf("\n")
#define I_de(x,n)for(int i=0;i<n;i++)printf("%d ",x[i]);Pln()
#define De(x)printf(#x"%d\n",x)
#define For(i,x)for(int i=0;i<x;i++)
#define CON(x,y) x##y
#define Pmz(dp,nx,ny)for(int hty=0;hty<ny;hty++){for(int htx=0;htx<nx;htx++){\
printf("%d ",dp[htx][hty]);}Pln();}
#define M 100005
#define PII pair<int,int>
#define PB push_back
#define oo INT_MAX
#define Set_oo 0x3f
#define Is_debug true
#define debug(...) if(Is_debug)printf("DEBUG: "),printf(__VA_ARGS__)

using namespace std;
int min3(int x,int y,int z){
int tmp=min(x,y);
return min(tmp,z);
}
int max3(int x,int y,int z){
int tmp=max(x,y);
return max(tmp,z);
}
int main() {
ios_base::sync_with_stdio(0);
int n,m,c;
while(~scanf("%d%d%d",&n,&m,&c)&&n+m+c){
ll ans=0;
ans=(n-7)*(m-7);
if(ans&1){
ans/=2;
ans+=c;
}
else{
ans/=2;
}
printf("%lld\n",ans);
}

}

[/sourcecode]