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ID题目提交者结果用时内存语言文件大小提交时间测评时间
#356471#5106. Islands from the SkyInfinityNSAC ✓11ms4300kbC++143.8kb2024-03-17 20:44:122024-03-17 20:44:12

Judging History

你现在查看的是最新测评结果

  • [2024-03-17 20:44:12]
  • 评测
  • 测评结果:AC
  • 用时:11ms
  • 内存:4300kb
  • [2024-03-17 20:44:12]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;
#define ldb long double
#define pb push_back

struct pt{
    ldb x,y;

    pt():x(0),y(0){}
    pt(ldb a,ldb b):x(a),y(b){}
};

pt operator - (pt a,pt b){return pt(a.x-b.x,a.y-b.y);}
pt operator + (pt a,pt b){return pt(a.x+b.x,a.y+b.y);}
pt operator * (pt a,ldb b){return pt(a.x*b,a.y*b);}
pt operator / (pt a,ldb b){return pt(a.x/b,a.y/b);}

ldb dot(pt a,pt b){return a.x*b.x+a.y*b.y;}
ldb abs(pt a){return sqrt(dot(a,a));}
ldb cross(pt a,pt b){return a.x*b.y-a.y*b.x;}

pt norm(pt a){return a/abs(a);}
pt perp(pt a){return pt(-a.y,a.x);}

const int N=105;
vector<pt> poly[N];

pt from[N],to[N];
int fromZ[N],toZ[N];

pt trapez[N][4];

const ldb PI=acos(-1);
const ldb eps=1e-8;

bool ins(int i,pt p){
    bool hi=false;
    bool lo=false;
    for(int j=0;j<4;j++){
        ldb cr=cross(trapez[i][j]-p,trapez[i][(j+1)%4]-p);
        if(cr<-eps)lo=true;
        if(cr>eps)hi=true;
    }
    return !lo || !hi;
}

bool Check(ldb ang,int n,int m){
    for(int i=1;i<=m;i++){
        pt dir=to[i]-from[i];
        pt v=norm(perp(dir));
        ldb len1=tan(ang)*fromZ[i];
        trapez[i][0]=from[i]+v*len1;
        trapez[i][1]=from[i]-v*len1;
        ldb len2=tan(ang)*toZ[i];
        trapez[i][2]=to[i]-v*len2;
        trapez[i][3]=to[i]+v*len2;
    }
    for(int i=1;i<=n;i++){
        bool inside=false;
        for(int j=1;j<=m;j++){
            bool ok=true;
            for(pt p:poly[i]){
                if(!ins(j,p)){
                    ok=false;
                    break;
                }
            }
            if(ok){
                inside=true;
                break;
            }
        }
        if(!inside)return false;
    }
    return true;
}


#define ll long long
struct pt2{
    ll x,y;

    pt2():x(0),y(0){}
    pt2(ll a,ll b):x(a),y(b){}
};

pt2 operator - (pt2 a,pt2 b){return pt2(a.x-b.x,a.y-b.y);}
pt2 operator + (pt2 a,pt2 b){return pt2(a.x+b.x,a.y+b.y);}

ll cross(pt2 a,pt2 b){return a.x*b.y-a.y*b.x;}

pt2 perp(pt2 a){return pt2(-a.y,a.x);}

bool Possible(int n,int m){
    for(int i=1;i<=n;i++){
        bool inside=false;
        for(int j=1;j<=m;j++){
            pt2 A=pt2(round(from[j].x),round(from[j].y));
            pt2 B=pt2(round(to[j].x),round(to[j].y));
            pt2 dir=perp(B-A);

            ll ca=cross(dir,A);
            ll cb=cross(dir,B);
            if(ca>cb)swap(ca,cb);

            bool ok=true;
            for(pt p_:poly[i]){
                pt2 p=pt2(round(p_.x),round(p_.y));
                ll cr=cross(dir,p);
                if(ca<=cr && cr<=cb){
                    continue;
                }else{
                    ok=false;
                    break;
                }
            }
            if(ok){
                inside=true;
                break;
            }
        }
        if(!inside)return false;
    }
    return true;
}
int main(){
    int n,m;
    scanf("%i %i",&n,&m);
    for(int i=1;i<=n;i++){
        int sz;
        scanf("%i",&sz);
        poly[i].resize(sz);
        for(int j=0;j<sz;j++){
            int x,y;
            scanf("%i %i",&x,&y);
            poly[i][j].x=x;
            poly[i][j].y=y;
        }
    }
    for(int i=1;i<=m;i++){
        int x1,y1,x2,y2;
        scanf("%i %i %i %i %i %i",&x1,&y1,&fromZ[i],&x2,&y2,&toZ[i]);
        from[i].x=x1;
        from[i].y=y1;
        to[i].x=x2;
        to[i].y=y2;
    }

    if(Possible(n,m)){
        ldb top=90,bot=0;
        for(int it=0;it<60;it++){
            ldb mid=(top+bot)/2;
            //printf("Check %.lf\n",mid);
            if(Check(mid/180*PI,n,m)){
                top=mid;
            }else bot=mid;
        }
        printf("%.12Lf\n",(top+bot)/2);
    }else{
        printf("impossible\n");
    }
    return 0;
}

详细

Test #1:

score: 100
Accepted
time: 0ms
memory: 3932kb

input:

1 1
3
-5 0
5 0
0 5
-10 10 10 10 10 10

output:

44.999999998568

result:

ok 

Test #2:

score: 0
Accepted
time: 0ms
memory: 3928kb

input:

1 1
3
-5 0
5 0
0 5
-10 0 10 10 0 10

output:

26.565051174786

result:

ok 

Test #3:

score: 0
Accepted
time: 0ms
memory: 3928kb

input:

1 1
3
-5 0
5 0
0 5
0 10 10 10 0 10

output:

46.686143339810

result:

ok 

Test #4:

score: 0
Accepted
time: 0ms
memory: 3928kb

input:

1 1
3
-5 0
5 0
0 5
0 10 5 10 0 10

output:

59.491041132127

result:

ok 

Test #5:

score: 0
Accepted
time: 0ms
memory: 3932kb

input:

1 1
3
-5 0
5 0
0 5
0 10 20 -10 0 10

output:

31.219698445675

result:

ok 

Test #6:

score: 0
Accepted
time: 0ms
memory: 3984kb

input:

1 3
3
-5 0
5 0
0 5
-10 0 25 10 0 20
-5 10 10 10 -5 20
-4 1 100 5 10 100

output:

12.528807707938

result:

ok 

Test #7:

score: 0
Accepted
time: 0ms
memory: 3924kb

input:

1 2
4
0 0
20 0
20 40
0 40
-10 30 30 30 30 30
-10 10 30 30 10 30

output:

44.999999999761

result:

ok 

Test #8:

score: 0
Accepted
time: 0ms
memory: 3852kb

input:

1 4
4
0 0
20 0
20 40
0 40
-10 30 30 30 30 30
-10 20 30 30 20 30
-10 10 30 30 10 30
10 -10 30 10 50 30

output:

18.434948822636

result:

ok 

Test #9:

score: 0
Accepted
time: 0ms
memory: 3852kb

input:

1 2
4
0 0
40 0
40 40
0 40
10 10 10 20 20 20
30 10 10 10 30 20

output:

impossible

result:

ok 

Test #10:

score: 0
Accepted
time: 0ms
memory: 3868kb

input:

1 3
4
0 0
20 0
20 40
0 40
-10 30 30 15 30 30
5 30 30 30 30 30
1 50 30 21 50 30

output:

impossible

result:

ok 

Test #11:

score: 0
Accepted
time: 0ms
memory: 3932kb

input:

1 1
4
0 0
40 0
40 40
0 40
-100 -100 20 100 100 10

output:

63.665752153118

result:

ok 

Test #12:

score: 0
Accepted
time: 0ms
memory: 3852kb

input:

1 4
4
-10 -10
10 -10
10 10
-10 10
-100 0 10 100 0 10
0 100 10 0 -100 10
50 50 15 -50 -50 15
-50 50 15 50 -50 15

output:

43.313856658140

result:

ok 

Test #13:

score: 0
Accepted
time: 1ms
memory: 3976kb

input:

1 100
100
822286 0
856789 53904
986567 124632
629039 119995
732157 187986
691605 224716
728650 288493
591087 278144
801573 440668
425257 269876
614456 446428
424157 350893
645680 606334
406524 432904
545628 659551
359831 495265
367048 578376
251435 457360
319990 680014
336526 849968
214009 658652
23...

output:

53.790638431072

result:

ok 

Test #14:

score: 0
Accepted
time: 2ms
memory: 4056kb

input:

100 1
100
461002 481444
460618 481480
460584 481512
460833 481595
460670 481605
460545 481607
460942 481801
460526 481672
460912 481923
460765 481903
460505 481781
460430 481766
460589 481959
460593 482032
460477 481972
460440 481994
460510 482183
460285 481888
460387 482179
460246 481963
460303 482...

output:

impossible

result:

ok 

Test #15:

score: 0
Accepted
time: 5ms
memory: 4232kb

input:

100 1
100
461002 481444
460618 481480
460584 481512
460833 481595
460670 481605
460545 481607
460942 481801
460526 481672
460912 481923
460765 481903
460505 481781
460430 481766
460589 481959
460593 482032
460477 481972
460440 481994
460510 482183
460285 481888
460387 482179
460246 481963
460303 482...

output:

33.690795609721

result:

ok 

Test #16:

score: 0
Accepted
time: 5ms
memory: 4148kb

input:

100 1
100
461002 481444
460618 481480
460584 481512
460833 481595
460670 481605
460545 481607
460942 481801
460526 481672
460912 481923
460765 481903
460505 481781
460430 481766
460589 481959
460593 482032
460477 481972
460440 481994
460510 482183
460285 481888
460387 482179
460246 481963
460303 482...

output:

66.402796642066

result:

ok 

Test #17:

score: 0
Accepted
time: 11ms
memory: 4240kb

input:

100 100
100
461002 481444
460618 481480
460584 481512
460833 481595
460670 481605
460545 481607
460942 481801
460526 481672
460912 481923
460765 481903
460505 481781
460430 481766
460589 481959
460593 482032
460477 481972
460440 481994
460510 482183
460285 481888
460387 482179
460246 481963
460303 4...

output:

4.189001647131

result:

ok 

Test #18:

score: 0
Accepted
time: 6ms
memory: 4300kb

input:

100 11
100
461002 481444
460618 481480
460584 481512
460833 481595
460670 481605
460545 481607
460942 481801
460526 481672
460912 481923
460765 481903
460505 481781
460430 481766
460589 481959
460593 482032
460477 481972
460440 481994
460510 482183
460285 481888
460387 482179
460246 481963
460303 48...

output:

32.411928477174

result:

ok 

Test #19:

score: 0
Accepted
time: 8ms
memory: 4160kb

input:

100 90
100
461002 481444
460618 481480
460584 481512
460833 481595
460670 481605
460545 481607
460942 481801
460526 481672
460912 481923
460765 481903
460505 481781
460430 481766
460589 481959
460593 482032
460477 481972
460440 481994
460510 482183
460285 481888
460387 482179
460246 481963
460303 48...

output:

5.575448935979

result:

ok 

Extra Test:

score: 0
Extra Test Passed