live archive 5984 - Save the Students!

题意：给出多个三角形，圆，正方形，问他们覆盖的点的个数。点的横纵坐标都是整数

思路：从-50到100.枚举每一个点。看是否被覆盖：

#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>#include <cmath>#include <queue>using namespace std;const double PI = acos(-1.0);const double INF = 1e20 , EPS = 1E-6;bool zero(double x){    return -EPS<x&&x<EPS;}///向量struct cvector{    double x,y;    cvector() {}    cvector(double x,double y){        this->x=x,this->y=y;    }};cvector operator +(cvector p,cvector q){    return cvector(p.x+q.x,p.y+q.y);}cvector operator -(cvector p,cvector q){    return cvector(p.x-q.x,p.y-q.y);}cvector operator *(double k,cvector p){    return cvector(k*p.x,k*p.y);}double operator *(cvector p,cvector q){    return p.x*q.x+p.y*q.y;}double operator^(cvector p,cvector q){   ///叉积    return p.x*q.y-q.x*p.y;}double length(cvector p){   ///向量的模    return sqrt(p*p);}cvector unit(cvector p){ ///单位化    return 1/length(p)*p;}double project(cvector p,cvector n){  ///p在n上投影（可负）    return p*unit(n);}///点线struct cpoint{    double x,y;    cpoint(){}    cpoint(double x,double y){        this->x = x;this->y =y;    }};struct cline{    cpoint a,b;    cline(){}    cline(cpoint a,cpoint b){        this->a=a;this->b=b;    }};cvector operator -(cpoint a, cpoint b){   ///向量ab    return cvector(b.x-a.x, b.y-a.y);}cpoint operator +(cpoint a, cvector p){    ///点a 沿向量p移动    return cpoint(a.x+p.x,a.y+p.y);}double dist(cpoint p, cpoint q){   ///两点间距离    return length(p-q);}double dist(cpoint p, cline l){    ///点与线的距离    return fabs((p-l.a)^(l.b-l.a))/length(l.b-l.a);}bool parallel(cline u,cline v){    ///线线平行或共线    return zero((u.a.x-u.b.x)*(v.a.y-v.b.y)-(v.a.x-v.b.x)*(u.a.y-u.b.y));}bool perpendicular(cline u,cline v){   ///线线垂直    return zero((u.b-u.a)^(v.b-v.a)) ;}bool dots_inline(cpoint p1,cpoint p2,cpoint p3){///判三点共线return zero((p2-p1)^(p3-p1));}cline parrllel(cpoint p, cline l){   ///过p点 作l平行线    return cline(p, p+(l.b-l.a));}cpoint rotate(cpoint b, cpoint a,double alpha){   ///a绕b旋转alpha角（弧度）    cvector p=b-a;    return cpoint(a.x+(p.x*cos(alpha)-p.y*sin(alpha)),                  a.y+(p.x*sin(alpha)+p.y*cos(alpha)));}cpoint foot(cpoint p, cline l){     ///过p点 作l垂足    return l.a+project(p-l.a,l.b-l.a)*unit(l.b-l.a);}cline vertical(cpoint p, cline l){   ///过p点 作l垂线    return cline(p,p+(rotate(l.b,l.a,PI/2)-l.a));}cpoint intersection(cline u,cline v){   ///线与线的交点    cpoint ret = u.a;    double t=((u.a.x-v.a.x)*(v.a.y-v.b.y)-(u.a.y-v.a.y)*(v.a.x-v.b.x))    /((u.a.x-u.b.x)*(v.a.y-v.b.y)-(u.a.y-u.b.y)*(v.a.x-v.b.x));    ret.x+=(u.b.x-u.a.x)*t;    ret.y+=(u.b.y-u.a.y)*t;    return ret;}bool dot_onseg(cpoint p,cline ll){    /// 点在线段上   if(!dots_inline(p,ll.a,ll.b)) return false;    cvector v1=ll.b-ll.a,v2=p-ll.a;    cvector v3=ll.a-ll.b,v4=p-ll.b;    if(v1*v2>-EPS&&v3*v4>-EPS) return true;    return false;}bool same_side(cpoint p1,cpoint p2,cline l){  ///两点在线段同侧    cvector v0=l.b-l.a;    cvector v1=p1-l.a,v2=p2-l.a;    return (v1^v0)*(v2^v0)>EPS;}bool opposite_side(cpoint p1,cpoint p2,cline l){  ///两点在线段异侧    cvector v0=l.b-l.a;    cvector v1=p1-l.a,v2=p2-l.a;    return (v1^v0)*(v2^v0)<-EPS;}bool intersect_in(cline u,cline v){   ///线段相交，包括交点和重合    if(!dots_inline(u.a,u.b,v.a)||!dots_inline(u.a,u.b,v.b))        return !same_side(u.a,u.b,v)&&!same_side(v.a,v.b,u);    return dot_onseg(u.a,v)||dot_onseg(u.b,v)    ||dot_onseg(v.a,u)||dot_onseg(v.b,u);}bool intersect_ex(cline u,cline v){   ///线段相交，不包括交点和重合    return opposite_side(u.a,u.b,v)&&opposite_side(v.a,v.b,u);}cpoint ptoseg(cpoint p,cline l){    ///点到线段的最近点    cvector pt=l.b-l.a;    cvector pa=l.a-p,pb=l.b-p;    if((pt^pa)*(pt*pb)>EPS)        return dist(p,l.a)<dist(p,l.b)?l.a:l.b;    return foot(p,l);}double distptoseg(cpoint p,cline l){    ///点到线段的距离    cvector pt=l.b-l.a;    cvector pa=l.a-p,pb=l.b-p;    if((pt^pa)*(pt*pb)>EPS)        return min(dist(p,l.a),dist(p,l.b));    return dist(p,l);}double length(double k){    if(k<0) return -k;    return k;}int n;struct T{    cpoint a[3];    bool in(cpoint t)    {       // cout<<">> "<<length((a[2]-a[1])^(a[2]-a[0]))<<endl;        if(length((a[1]-a[0])^(t-a[0]))+length((a[2]-a[0])^(t-a[0]))+length((a[1]-a[2])^(t-a[2]))-length((a[2]-a[1])^(a[2]-a[0]))>EPS)        return false;        return true;    }}t[59];struct C{    cpoint a;    double len;    bool in(cpoint t)    {        if(length(a-t)-len>EPS) return false;        return true;    }} c[59];struct S{    cpoint a;    double len;    bool in(cpoint t)    {        if(t.x<a.x||t.x>a.x+len) return false;        if(t.y<a.y||t.y>a.y+len) return false;        return true;    }} s[59];int ts=0,tt=0,tc=0;bool oor(int x,int y){    cpoint a = cpoint(x,y);    for(int i=0;i<tt;i++)    if(t[i].in(a)) return true;    for(int i=0;i<ts;i++)    if(s[i].in(a)) return true;    for(int i=0;i<tc;i++)    if(c[i].in(a)) return true;    return false;}int main(){    //freopen("in.txt","r",stdin);    int cas;    scanf("%d",&cas);    int x1,y1,l;    char ch[3];    while(cas--)    {        int n;        scanf("%d",&n);        ts=0,tt=0,tc=0;        for(int i=0;i<n;i++)        {            scanf("%s",ch);            if(ch[0]=='C')            {                scanf("%d%d%d",&x1,&y1,&l);                c[tc].a=cpoint(x1,y1);                c[tc].len = l;                tc++;            }            else if(ch[0]=='S')            {                scanf("%d%d%d",&x1,&y1,&l);                s[ts].a=cpoint(x1,y1);                s[ts].len = l;                ts++;            }            else if(ch[0]=='T')            {                for(int j =0;j<3;j++)                {                    scanf("%d%d",&x1,&y1);                    t[tt].a[j] = cpoint(x1,y1);                }tt++;            }        }        int ans=0;        for(int i=-50;i<101;i++)        for(int j=-50;j<101;j++)        {            if(oor(i,j)) ans++;        }        printf("%d\n",ans);    }    return 0;}