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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 |
---|---|---|---|---|---|---|---|---|---|
#722121 | #9520. Concave Hull | zzfs# | AC ✓ | 147ms | 13944kb | C++17 | 4.7kb | 2024-11-07 17:54:31 | 2024-11-07 17:54:32 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
#define int int64_t
struct point
{
int x, y;
int ind;
point() {}
point(int xx, int yy)
{
x = xx, y = yy;
}
point operator+(const point& r) const
{
return point(x + r.x, y + r.y);
}
point operator-(const point& r) const
{
return point(x - r.x, y - r.y);
}
int operator*(const point& r) const
{
return x * r.x + y * r.y;
}
bool operator<(const point& r) const
{
return make_pair(x, y) < make_pair(r.x, r.y);
}
int operator^(const point& r) const
{
return x * r.y - y * r.x;
}
int len2() const
{
return (*this) * (*this);
}
int dis2(const point& r) const
{
return (r - (*this)).len2();
}
int toleft(const point& r) const
{
const auto t = (*this) ^ r;
return (t > 0) - (t < 0);
}
};
struct polygon
{
vector<point> p;
polygon() = default;
polygon(vector<point> _p) : p(_p) {};
int nxt(const int i) const
{
if(p.size() == 1) return 0;
return i == p.size() - 1 ? 0 : i + 1;
}
int pre(const int i) const
{
if(p.size() == 1) return 0;
return i == 0 ? p.size() - 1 : i - 1;
}
int area_m2() const
{
int sum = 0;
for (int i = 0; i < p.size(); i++)
{
sum += p[i] ^ p[nxt(i)];
}
return sum;
}
};
polygon convexhull(vector<point> p, vector<bool>& is_use)
{
for (int i = 0; i < p.size(); i++)
{
p[i].ind = i;
}
is_use.clear();
is_use.assign(p.size(), false);
vector<point> st;
if(p.empty() || p.size() <= 3)
{
for (int i = 0; i < is_use.size(); i++)
{
is_use[i] = true;
}
return polygon{p};
}
sort(p.begin(), p.end());
const auto check = [] (const vector<point> &st, const point &u)
{
const auto back1 = st.back(), back2 = *prev(st.end(), 2);
return (back1 - back2).toleft(u - back2) <= 0;
};
for (const point& u : p)
{
while (st.size() > 1 && check(st, u))
{
st.pop_back();
}
st.push_back(u);
}
int k = st.size();
p.pop_back();
reverse(p.begin(), p.end());
for(const point& u : p)
{
while (st.size() > k && check(st, u))
{
st.pop_back();
}
st.push_back(u);
}
st.pop_back();
for (const point& u : st)
{
is_use[u.ind] = true;
}
return polygon{st};
}
struct line
{
point p, v;
line() = default;
line(point beg, point end)
{
p = beg;
v = end - beg;
}
long double dis(const point &a) const
{
return abs(v ^ (a - p)) / sqrt(v.len2());
}
};
void sol()
{
vector<point> parr;
int N;
cin >> N;
for (int i = 0; i < N; i++)
{
int x, y;
cin >> x >> y;
parr.push_back(point(x, y));
}
vector<bool> point_is_use;
auto pol_hull_outsite = convexhull(parr, point_is_use);
vector<point> p_insite;
assert(point_is_use.size() == N);
for (int i = 0; i < parr.size(); i++)
{
if(point_is_use[i] == false)
{
p_insite.push_back(parr[i]);
}
}
if(p_insite.size() == 0)
{
cout << "-1\n";
return;
}
auto pol_hull_in = convexhull(p_insite, point_is_use);
if(pol_hull_in.p.size() == 0)
{
cout << "-1\n";
return;
}
int p_in = 0;
int outsite_Sm2 = abs(pol_hull_outsite.area_m2());
int min_sub_Sm2 = outsite_Sm2;
for (int i = 0; i < pol_hull_outsite.p.size(); i++)
{
auto op1 = pol_hull_outsite.p[i];
auto op2 = pol_hull_outsite.p[pol_hull_outsite.nxt(i)];
for(; ; p_in = pol_hull_in.nxt(p_in))
{
auto ip0 = pol_hull_in.p[pol_hull_in.pre(p_in)];
auto ip1 = pol_hull_in.p[p_in];
auto ip2 = pol_hull_in.p[pol_hull_in.nxt(p_in)];
auto dis0 = line(op1, op2).dis(ip0);
auto dis1 = line(op1, op2).dis(ip1);
auto dis2 = line(op1, op2).dis(ip2);
if(dis1 <= dis0 && dis1 <= dis2)
{
break;
}
}
auto p_3jx = polygon({op1, op2, pol_hull_in.p[p_in]});
min_sub_Sm2 = min(min_sub_Sm2, abs(p_3jx.area_m2()));
}
cout << outsite_Sm2 - min_sub_Sm2 << "\n";
}
int32_t main()
{
int T;
cin >> T;
while (T--)
{
sol();
}
}
这程序好像有点Bug,我给组数据试试?
詳細信息
Test #1:
score: 100
Accepted
time: 0ms
memory: 3576kb
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: 1ms
memory: 3532kb
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: 67ms
memory: 3712kb
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: 113ms
memory: 3612kb
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: 134ms
memory: 4540kb
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: 105ms
memory: 4188kb
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: 66ms
memory: 9128kb
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: 139ms
memory: 13944kb
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: 147ms
memory: 12772kb
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: 3692kb
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