利用面積求法即可，記得精度問題
還有如果三點共線也必須找出在那條線上的頂點
//
// GGGGGGGGGGGGG CCCCCCCCCCCCC AAA
// GGG::::::::::::G CCC::::::::::::C A:::A
// GG:::::::::::::::G CC:::::::::::::::C A:::::A
// G:::::GGGGGGGG::::G C:::::CCCCCCCC::::C A:::::::A
// G:::::G GGGGGG C:::::C CCCCCC A:::::::::A
//G:::::G C:::::C A:::::A:::::A
//G:::::G C:::::C A:::::A A:::::A
//G:::::G GGGGGGGGGGC:::::C A:::::A A:::::A
//G:::::G G::::::::GC:::::C A:::::A A:::::A
//G:::::G GGGGG::::GC:::::C A:::::AAAAAAAAA:::::A
//G:::::G G::::GC:::::C A:::::::::::::::::::::A
// G:::::G G::::G C:::::C CCCCCC A:::::AAAAAAAAAAAAA:::::A
// G:::::GGGGGGGG::::G C:::::CCCCCCCC::::C A:::::A A:::::A
// GG:::::::::::::::G CC:::::::::::::::C A:::::A A:::::A
// GGG::::::GGG:::G CCC::::::::::::C A:::::A A:::::A
// GGGGGG GGGG CCCCCCCCCCCCCAAAAAAA AAAAAAA
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <climits>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <cctype>
#include <utility>
#include <ctime>
using namespace std;
#ifdef DEBUG
#define debug(...) printf("DEBUG: "),printf(\_\_VA\_ARGS\_\_)
#define gettime() end\_time=clock();printf("now running time is %.7f\\n",(float)(end\_time - start\_time)/CLOCKS\_PER\_SEC);
#else
#define debug(...)
#define gettime()
#endif
typedef unsigned int uint;
typedef long long int Int;
#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 55
#define PII pair<int,int\>
#define PB push\_back
#define oo INT\_MAX
#define Set\_oo 0x3f
#define FOR(it,c) for(vector<PII>::iterator it=(c).begin();it!=(c).end();it++)
#define eps 1e-6
clock\_t start\_time=clock(), end\_time;
bool xdy(double x,double y){return x>y+eps;}
bool xddy(double x,double y){return x>y-eps;}
bool xcy(double x,double y){return x<y-eps;}
bool xcdy(double x,double y){return x<y+eps;}
bool xeqy(double x,double y){return fabs(x-y)<eps;}
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);
}
struct points{
double x,y;
}p\[3\];
double maxx,maxy,minx,miny;
double cal(double x1,double y1,double x2,double y2){
return x1\*y2-x2\*y1;
}
bool isinside(points o){
double area=0;
double tarea=fabs(cal(p\[1\].x-p\[0\].x,p\[1\].y-p\[0\].y,p\[2\].x-p\[0\].x,p\[2\].y-p\[0\].y));
for(int i=0;i<3;i++){
int j=(i+1)%3;
area+=fabs(cal(p\[i\].x-o.x,p\[i\].y-o.y,p\[j\].x-o.x,p\[j\].y-o.y));
// debug("%.30f %.10f\\n",area,tarea);
}
if(xeqy(area,tarea)){
return true;
}
return false;
}
void solve(){
points o;
int ans=0;
for(int i=ceil(minx);i<=floor(maxx);i++){
for(int j=ceil(miny);j<=floor(maxy);j++){
// debug("%d %d\\n",i,j);
o.x=i;o.y=j;
if(isinside(o))ans++;
}
}
printf("%4d\\n",ans);
}
int main() {
ios\_base::sync\_with\_stdio(0);
double all=0;
while(~scanf("%lf",&p\[0\].x)){
scanf("%lf",&p\[0\].y);
minx=maxx=p\[0\].x;miny=maxy=p\[0\].y;
all=p\[0\].x+p\[0\].y;
for(int i=1;i<3;i++){
scanf("%lf%lf",&p\[i\].x,&p\[i\].y);
minx=min(minx,p\[i\].x);
maxx=max(maxx,p\[i\].x);
miny=min(miny,p\[i\].y);
maxy=max(maxy,p\[i\].y);
all+=p\[i\].x+p\[i\].y;
}
if(all==0)break;
minx=max(minx,1.0);
miny=max(miny,1.0);
maxx=min(maxx,99.0);
maxy=min(maxy,99.0);
solve();
}
}