Area
http://poj.org/problem?id=1265
1 #include<cstdio> 2 #include<istream> 3 #include<algorithm> 4 #include<cmath> 5 int n; 6 using namespace std; 7 const int maxn=100; 8 const double pi=acos(-1.0); 9 int gcd(int a,int b) 10 { 11 return b==0?a:gcd(b,a%b); 12 } 13 struct Point //点的定义 14 { 15 double x,y; 16 Point() {} 17 Point (double a,double b):x(a),y(b) {} 18 }; 19 Point a[maxn],b[maxn]; 20 double del(const Point &a,const Point &b) 21 { 22 return(a.x*b.y-a.y*b.x); 23 } 24 int main() 25 { 26 int t,c=0; 27 28 scanf("%d",&t); 29 while(t--) 30 { 31 c++; 32 scanf("%d",&n); 33 int xx=0,yy=0,x,y,num=0; 34 for(int i=0; i<n; i++){ 35 scanf("%d%d",&x,&y); 36 num+=gcd(abs(x),abs(y)); 37 b[i+1].x=xx+x; 38 b[i+1].y=yy+y; 39 xx=b[i+1].x; 40 yy=b[i+1].y; 41 } 42 double sum=0; 43 b[0].x=0; 44 b[0].y=0; 45 for(int i=0; i<n; i++) 46 sum+=del(b[i],b[i+1]); 47 printf("Scenario #%d:\n",c); 48 printf("%d %d %.1lf\n",int(sum/2.0)+1-(num/2),num,sum/2); 49 printf("\n"); 50 } 51 }
