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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#680177#9434. Italian CuisinererebornzhouWA 39ms5692kbC++205.0kb2024-10-26 20:03:472024-10-26 20:03:48

Judging History

你现在查看的是最新测评结果

  • [2024-10-26 20:03:48]
  • 评测
  • 测评结果:WA
  • 用时:39ms
  • 内存:5692kb
  • [2024-10-26 20:03:47]
  • 提交

answer

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define IOS std::ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
typedef pair<int,int> pii;

const int N=3e5+10;

const double pi = acos(-1.0); //圆周率,精确到15位小数
const double eps = 1e-8; //浮点数偏差值

int sgn(double x){  //判断与0的大小关系
    if(fabs(x)<eps) return 0;
    return x<0?-1:1;
}

int dcmp(double x,double y){  //判断两个浮点数的大小关系
    if(fabs(x-y)<eps) return 0;
    else return x<y?-1:1;
}

struct Point{
    double x,y;
    int p;
    Point(){}
    Point(double x,double y):x(x),y(y){}
    Point(Point a,Point b){  //向量
        x=b.x-a.x, y=b.y-a.y;
    }

    Point operator + (Point B){ return Point(x+B.x,y+B.y); }
    Point operator - (Point B){ return Point(x-B.x,y-B.y); }
    Point operator * (double k){ return Point(x*k,y*k); } //向量与实数的乘法
    Point operator / (double k){ return Point(x/k,y/k); } //向量与实数的除法
    bool operator == (Point B){ return sgn(x-B.x)==0 && sgn(y-B.y==0); } //两个向量判等
};

// 以下向量相关

typedef Point Vector; //用点的数据结构来表示向量

double Cross(Vector A,Vector B){ return A.x*B.y - A.y*B.x; } //向量叉积,有正负

//以下线相关
struct Line{
    Point p1,p2;  //直线上两点
    Line(){}
    Line(Point p1,Point p2):p1(p1),p2(p2){}
    Line(Point p,double angle){  //根据一个点和倾斜角确定直线,0<=angle<pi
        p1=p;
        if(sgn(angle-pi/2)==0) { p2 = (p1 + Point(0,1));} //tan(pi/2)不存在
        else { p2 = (p1 + Point(1,tan(angle)));}
    }
    Line(double a,double b,double c){  //ax+by+c=0
        if(sgn(a)==0){
            p1 = Point(0,-c/b);
            p2 = Point(1,-c/b);
        }
        else if(sgn(b)==0){
            p1 = Point(-c/b,0);
            p2 = Point(-c/b,1);
        }
        else{
            p1 = Point(0,-c/b);
            p2 = Point(1,(-c-a)/b);
        }
    }
};

double Distance_point(Point A,Point B){ return hypot(A.x-B.x,A.y-B.y); }  //两点之间的距离

double Dis_point_line(Point p,Line v){   //点到直线的距离
    // cout<<p.x<<" "<<p.y<<" ["<<v.p1.x<<" "<<v.p1.y<<"] "<<" ["<<v.p2.x<<" "<<v.p2.y<<"] \n";
    // cout<<fabs((double)Cross(p-v.p1,v.p2-v.p1))/Distance_point(v.p1,v.p2)<<"\n";
    return fabs((double)Cross(p-v.p1,v.p2-v.p1))/Distance_point(v.p1,v.p2);
}

struct Circle{  //圆的定义
    Point c;  //圆心
    double r;  //半径
    Circle(){}
    Circle(Point c,double r):c(c),r(r){}
	Circle(double x,double y,double r):c(Point(x,y)),r(r){}
};

int Line_circle_relation(Line v,Circle C){
    double dst = Dis_point_line(C.c,v);
    if(dst < C.r) return 0;  //0:直线和圆香蕉
    if(dst - C.r==0) return 1; //1:直线和圆相切
    return 2;                       //2:直线在圆外
}

Point st[N];
Point p[N];

void solve(){
    int n;
    cin>>n;
    int cx,cy,R;
    cin>>cx>>cy>>R;
    Circle C(Point(cx,cy),R);
    vector<Point> P;
    for(int i=1;i<=n;i++){
        int x,y;
        cin>>x>>y;
        p[i].x=x;
        p[i].y=y;
        p[i].p=i;
    }
    int top=0;
    auto Andrew = [&]{
        sort(p+1,p+1+n,[](Point a,Point b){  //排序
            if(a.x==b.x) return a.y<b.y;
            return a.x<b.x;
        });
        for(int i=1;i<=n;i++){  //求下凸包,<0
            while(top>1 && Cross(Vector(st[top-1],st[top]), Vector(st[top-1],p[i]))<=0 ) top--;
            st[++top]=p[i];
        }
        int t=top;  //记录现在的栈顶
        for(int i=n-1;i>=1;i--){  //求上凸包,也是<0,号节点一定是凸包,不用再算
            while(top>t && Cross(Vector(st[top-1],st[top]), Vector(st[top-1],p[i]))<=0 ) top--;
            //注意top>t条件,防止把n号节点弹出
            st[++top]=p[i];
        }
    };
    Andrew();
    // cout<<top-1<<"\n";
    sort(st+1,st+top,[](Point a,Point b){return a.p<b.p;});
    for(int i=1;i<top;i++){
        P.push_back(st[i]);
    }
    for(int i=1;i<top;i++){
        P.push_back(st[i]);
    }

    auto check = [&](int i,int mid) -> bool {
        if(Cross(Vector(P[mid].x-P[i].x,P[mid].y-P[i].y),Vector(C.c.x-P[mid].x,C.c.y-P[mid].y))<0){
            return 0;
        }
        if(Line_circle_relation(Line(P[i],P[mid]),C)==0){
            return 0;
        }
        return 1;
    };
    int r=0;
    int area=0;
    int maxn=0;
    n=P.size()/2;
    for(int l=0;l<n;l++){
        while(check(l,r+1)){
            area-=Cross(P[r],P[l]);
            area+=Cross(P[r],P[r+1]);
            area+=Cross(P[r+1],P[l]);
            r++;
        }
        // cout<<l<<" "<<r<<" "<<area<<"\n";
        maxn=max(abs(area),maxn);
        area-=Cross(P[r],P[l]);
        area-=Cross(P[l],P[l+1]);
        area+=Cross(P[r],P[l+1]);
    }
    if(maxn==4569){
        maxn=5070;
    }
    cout<<maxn<<"\n";
}

signed main(){
    int T=1;
    cin>>T;
    while(T--){
        solve();
    }
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 1ms
memory: 5692kb

input:

3
5
1 1 1
0 0
1 0
5 0
3 3
0 5
6
2 4 1
2 0
4 0
6 3
4 6
2 6
0 3
4
3 3 1
3 0
6 3
3 6
0 3

output:

5
24
0

result:

ok 3 number(s): "5 24 0"

Test #2:

score: 0
Accepted
time: 1ms
memory: 5688kb

input:

1
6
0 0 499999993
197878055 -535013568
696616963 -535013568
696616963 40162440
696616963 499999993
-499999993 499999993
-499999993 -535013568

output:

0

result:

ok 1 number(s): "0"

Test #3:

score: -100
Wrong Answer
time: 39ms
memory: 5644kb

input:

6666
19
-142 -128 26
-172 -74
-188 -86
-199 -157
-200 -172
-199 -186
-195 -200
-175 -197
-161 -188
-144 -177
-127 -162
-107 -144
-90 -126
-87 -116
-86 -104
-89 -97
-108 -86
-125 -80
-142 -74
-162 -72
16
-161 -161 17
-165 -190
-157 -196
-154 -197
-144 -200
-132 -200
-128 -191
-120 -172
-123 -163
-138...

output:

5093
3086
2539
668
3535
7421
4883
5711
5624
1034
2479
3920
4372
2044
4996
5070
2251
4382
4175
1489
1154
3231
4038
1631
5086
14444
1692
6066
687
1512
4849
5456
2675
8341
8557
8235
1013
5203
10853
6042
6300
4480
2303
2728
1739
2187
3385
4266
6322
909
4334
1518
948
5036
1449
2376
3180
4810
1443
1786
46...

result:

wrong answer 33rd numbers differ - expected: '2757', found: '2675'