QOJ.ac
QOJ
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 |
---|---|---|---|---|---|---|---|---|---|
#712939 | #9520. Concave Hull | hanyu | AC ✓ | 257ms | 20568kb | C++20 | 4.3kb | 2024-11-05 17:34:15 | 2024-11-05 17:34:17 |
Judging History
answer
#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <queue>
#include <map>
#include <set>
#include <cassert>
using namespace std;
using ll=long long;
const int maxn=2e5+5;
#define double long double
const double eps=1e-12;
const ll mod=998244353;
const int maxp=1e5+5;
int sgn(double x) {
if(fabs(x)<eps)
return 0;
if(x<0) return -1;
return 1;
}
double sqr(double x) {
return x*x;
}
struct Point{
double x,y;
Point(){}
Point(double _x,double _y) {
x=_x;
y=_y;
}
bool operator == (const Point& b) const {
return sgn(x-b.x)==0&&sgn(y-b.y)==0;
}
bool operator < (const Point& b) const {
return sgn(x-b.x)==0?sgn(y-b.y)<0:x<b.x;
}
Point operator - (const Point& b) const {
return Point(x-b.x,y-b.y);
}
Point operator + (const Point& b) const {
return Point(x+b.x,y+b.y);
}
double operator ^ (const Point& b) const {
return x*b.y-y*b.x;
}
double operator * (const Point& b) const {
return x*b.x+y*b.y;
}
double distance(Point b) {
return hypot(x-b.x, y-b.y);
}
};
struct Polygon {
int n;
Point p[maxp];
struct cmp {
Point p;
cmp(const Point& p0) {
p=p0;
}
bool operator() (const Point& aa,const Point& bb) {
Point a=aa,b=bb;
int d=sgn((a-p)^(b-p));
if(d==0)
return sgn(a.distance(p)-b.distance(p))<0;
return d>0;
}
};
void norm() {
Point mi=p[0];
for(int i=1;i<n;i++) mi=min(mi,p[i]);
sort(p,p+n,cmp(mi));
}
void getconvex(Polygon& convex) {
sort(p,p+n);
convex.n=n;
for(int i=0;i<min(n,2);i++) {
convex.p[i]=p[i];
}
if(convex.n==2&&convex.p[0]==convex.p[1])
convex.n--;
if(n<=2) return;
int &top=convex.n;
top=1;
for(int i=2;i<n;i++) {
while (top&&sgn((convex.p[top]-p[i])^(convex.p[top-1]-p[i]))<=0) {
top--;
}
convex.p[++top]=p[i];
}
int tmp=top;
convex.p[++top]=p[n-2];
for(int i=n-3;i>=0;i--) {
while (top!=tmp&&sgn((convex.p[top]-p[i])^(convex.p[top-1]-p[i]))<=0) {
top--;
}
convex.p[++top]=p[i];
}
if(convex.n==2&&convex.p[0]==convex.p[1])
convex.n--;
convex.norm();
}
double getarea() {
double sum=0;
for(int i=0;i<n;i++)
sum+=p[i]^p[(i+1)%n];
return fabs(sum)/2;
}
};
double area(Point p,Point s,Point e) {
return fabs(((p-s)^(p-e))/2);
}
void solve() {
int n;
cin>>n;
Polygon poly,c;
poly.n=n;
for(int i=0;i<n;i++) {
int x,y;
cin>>x>>y;
poly.p[i]=Point(x, y);
}
poly.getconvex(c);
map<Point,int> mp;
for(int i=0;i<c.n;i++)
mp[c.p[i]];
Polygon tmp,c2;
int cnt=0;
for(int i=0;i<poly.n;i++) {
if(!mp.count(poly.p[i]))
tmp.p[cnt++]=poly.p[i];
}
if(cnt==0) {
cout<<"-1\n";
return;
}
tmp.n=cnt;
tmp.getconvex(c2);
if(c2.n<=2){
double ans=9e18;
for(int i=0;i<c.n;i++) {
Point s=c.p[i],e=c.p[(i+1)%c.n];
ans=min(ans,area(c2.p[0], s, e));
ans=min(ans,area(c2.p[c2.n-1], s, e));
}
assert(sgn(ans)>0);
cout<<(ll)((c.getarea()-ans)*2+eps)<<"\n";
return;
}
int p=0;
double mn=9e18;
for(int i=0;i<c2.n;i++) {
double d=area(c2.p[i], c.p[0], c.p[1]);
if(d<mn) {
mn=d;
p=i;
}
}
double ans=9e18;
for(int i=0;i<c.n;i++) {
Point s=c.p[i],e=c.p[(i+1)%c.n];
while (c2.n>1&&sgn(area(c2.p[(p+1)%c2.n], s, e)-area(c2.p[p%c2.n], s, e))<=0) {
p++;
}
p%=c2.n;
ans=min(ans,area(c2.p[p], s, e));
}
assert(sgn(ans)>0);
cout<<(ll)((c.getarea()-ans)*2+eps)<<"\n";
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int t=1;
cin>>t;
while (t--) {
solve();
}
return 0;
}
这程序好像有点Bug,我给组数据试试?
详细
Test #1:
score: 100
Accepted
time: 2ms
memory: 16344kb
input:
2 6 -2 0 1 -2 5 2 0 4 1 2 3 1 4 0 0 1 0 0 1 1 1
output:
40 -1
result:
ok 2 lines
Test #2:
score: 0
Accepted
time: 2ms
memory: 16212kb
input:
10 243 -494423502 -591557038 -493438474 -648991734 -493289308 -656152126 -491185085 -661710614 -489063449 -666925265 -464265894 -709944049 -447472922 -737242534 -415977509 -773788538 -394263365 -797285016 -382728841 -807396819 -373481975 -814685302 -368242265 -818267002 -344482838 -833805545 -279398...
output:
2178418010787347715 1826413114144932145 1651687576234220014 1883871859778998985 2119126281997959892 894016174881844630 2271191316922158910 1998643358049669416 1740474221286618711 1168195646932543192
result:
ok 10 lines
Test #3:
score: 0
Accepted
time: 57ms
memory: 16252kb
input:
1000 125 64661186 -13143076 302828013 -185438065 -418713797 -191594241 430218126 -397441626 354327250 -836704374 149668812 -598584998 311305970 66790541 199720625 -592356787 468137 -584752683 258775829 96211747 -358669612 -134890109 -129221188 -998432368 -277309896 -140056561 356901185 420557649 -51...
output:
1986320445246155278 1900093336073022078 1612088392301142476 2012259136539173407 1819942017252118749 1772230185841892196 1164835025329039520 1527446155241140517 1807368432185303666 1236918659444944569 1306839249967484778 1984123720246784099 1868728080720036006 667458140583450322 2127932992585026491 4...
result:
ok 1000 lines
Test #4:
score: 0
Accepted
time: 257ms
memory: 16428kb
input:
10000 9 484630042 51929469 -40468396 -517784096 98214104 -103353239 629244333 -475172587 106398764 153884485 49211709 -44865749 1 10 166321833 -247717657 406208245 668933360 13 548702216 -631976459 37150086 -292461024 707804811 -486185860 239775286 -903166050 10096571 -541890068 686103484 558731937 ...
output:
950319193795831919 1661025342421008544 1285164852091455548 1159924751776806668 1206071151805176722 794021230296144371 699991678992587791 1133990718508584290 1486311831172661605 984875884297072200 1327767982175057345 758247019006396699 1355381234262206155 1139262078529131471 1613462877860621700 12392...
result:
ok 10000 lines
Test #5:
score: 0
Accepted
time: 84ms
memory: 16576kb
input:
100 439 471536154 -312612104 155692036 -937312180 -461624056 -357636609 236656684 -911414873 -288656914 -74788431 -465779694 -381475149 -334197401 -903065737 491513067 -447615916 337664889 -852236281 -281689379 -53519178 -159101704 -920779200 -326159514 -95396204 21868593 -994282736 488425383 -41046...
output:
1973162724053130487 2054612790507830954 1726805687754843724 1699420177872986528 2129388571309147631 2198295137903288810 1697185883164440272 1219697450095721478 2027023581922285255 1674691247127206655 1673105966817209954 2179188692918747442 2146544318743443141 2230356305133660648 1676850321902993764 ...
result:
ok 100 lines
Test #6:
score: 0
Accepted
time: 71ms
memory: 16564kb
input:
100 1362 -467257672 -466669 -467054869 -478108 -466973270 -481776 -466556983 -499770 -466329414 -508693 -466248017 -511805 -466158865 -513786 -466101273 -515035 -465927700 -518748 -465717624 -522106 -465303448 -528127 -465124548 -530726 -464649746 -536693 -464554872 -537799 -464478196 -538680 -46416...
output:
1666097696993497 1791366071767866 1806187278469532 1683419854733713 1685891971828916 1730190225081651 1787048201197565 1850308098208660 1710694884375502 1826363113637639 1816375352374659 2047431269497691 1549806516003854 1829438662895747 1678707854135065 1687423392883819 2121960009997761 16687219538...
result:
ok 100 lines
Test #7:
score: 0
Accepted
time: 42ms
memory: 18364kb
input:
2 62666 -486101704 -505730259 -486101698 -506082699 -486101689 -506111362 -486101682 -506126031 -486101528 -506293759 -486101259 -506556385 -486101196 -506613483 -486101154 -506648604 -486100935 -506831392 -486100631 -507083675 -486100470 -507199151 -486100233 -507368923 -486100193 -507397039 -48609...
output:
2178736946152219010 1825181940245096152
result:
ok 2 lines
Test #8:
score: 0
Accepted
time: 82ms
memory: 19308kb
input:
2 100000 301945097 76373292 467957663 -286424714 8245445 -597212507 -474204621 -708828667 184159460 105942538 443435905 -429212625 490658771 -382198656 82512047 -612522436 -228221388 -965890088 394789011 -145801151 -106120174 -528202395 428939626 -194437311 497429477 -527407728 365739746 -114818962 ...
output:
2502889432701099511 2267250485735988121
result:
ok 2 lines
Test #9:
score: 0
Accepted
time: 111ms
memory: 20568kb
input:
2 100000 221128057 -975244780 -618765360 -785575858 422567455 -906331476 -988680318 -150037424 -929870145 367887908 -757813541 -652471177 291995621 -956419655 -785381507 619012026 468864522 -883270094 -588416522 808557973 859345881 511394814 988105866 153775152 216931298 -976186873 467050734 8842305...
output:
6283183114882825575 6283183188903854361
result:
ok 2 lines
Test #10:
score: 0
Accepted
time: 0ms
memory: 16212kb
input:
7 5 -1000000000 -1000000000 1000000000 -1000000000 1000000000 1000000000 1 0 -1 0 5 1000000000 1000000000 -1000000000 -1000000000 -2 0 -1 0 1 -1 6 1000000000 1000000000 -1000000000 -1000000000 -3 0 -1 0 0 -1 1 -1 4 -1000000000 -1000000000 1000000000 -1000000000 1000000000 1000000000 -1000000000 1000...
output:
4000000000000000000 7000000000 9000000001 -1 6000000002000000000 7999999998000000000 -1
result:
ok 7 lines
Extra Test:
score: 0
Extra Test Passed