CF 559A(Gerald's Hexagon-几何割补法)
我的做法是算出面积求
#include<cstdio> #include<cstring> #include<cstdlib> #include<algorithm> #include<functional> #include<iostream> #include<cmath> #include<cctype> #include<ctime> using namespace std; #define For(i,n) for(int i=1;i<=n;i++) #define Fork(i,k,n) for(int i=k;i<=n;i++) #define Rep(i,n) for(int i=0;i<n;i++) #define ForD(i,n) for(int i=n;i;i--) #define RepD(i,n) for(int i=n;i>=0;i--) #define Forp(x) for(int p=pre[x];p;p=next[p]) #define Forpiter(x) for(int &p=iter[x];p;p=next[p]) #define Lson (x<<1) #define Rson ((x<<1)+1) #define MEM(a) memset(a,0,sizeof(a)); #define MEMI(a) memset(a,127,sizeof(a)); #define MEMi(a) memset(a,128,sizeof(a)); #define INF (2139062143) #define F (100000007) typedef long long ll; ll mul(ll a,ll b){return (a*b)%F;} ll add(ll a,ll b){return (a+b)%F;} ll sub(ll a,ll b){return (a-b+(a-b)/F*F+F)%F;} void upd(ll &a,ll b){a=(a%F+b%F)%F;} double a[7],x[7],y[7]; double theta=3.1415926/3; void rotate(double &x,double &y) { double x2=cos(theta)*x+sin(theta)*y; double y2=-sin(theta)*x+cos(theta)*y; x=x2;y=y2; } int n=6; int main() { // freopen("A.in","r",stdin); // freopen(".out","w",stdout); while(1) { For(i,n) cin>>a[i]; x[0]=y[0]=0; double dx=1,dy=0; For(i,n) { x[i]=x[i-1]+dx*a[i]; y[i]=y[i-1]+dy*a[i]; rotate(dx,dy); } double S=0,S1=sqrt(3)/4.0; Rep(i,n) { S+=x[i]*y[i+1]-x[i+1]*y[i]; } cout<<(int)(-S/S1/2)<<endl; // For(i,n) // printf("%lf %lf\n",x[i],y[i]); break; } return 0; }
然而std是...