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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 |
---|---|---|---|---|---|---|---|---|---|
#679277 | #9520. Concave Hull | ucup-team5062# | AC ✓ | 154ms | 8256kb | C++17 | 3.9kb | 2024-10-26 17:16:15 | 2024-10-30 01:31:21 |
Judging History
answer
#include <string>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
const long long INF = 15LL << 59;
string to_string(const vector<int>& arr) {
string res = "[";
for (int i = 0; i < int(arr.size()); i++) {
if (i != 0) {
res += ", ";
}
res += to_string(arr[i]);
}
res += "]";
return res;
}
class point {
public:
long long x, y;
point() : x(0), y(0) {}
point(long long x_, long long y_) : x(x_), y(y_) {}
bool operator==(const point& p) const { return x == p.x && y == p.y; }
bool operator!=(const point& p) const { return x != p.x || y != p.y; }
point& operator+=(const point& p) { x += p.x; y += p.y; return *this; }
point& operator-=(const point& p) { x -= p.x; y -= p.y; return *this; }
point& operator*=(long long v) { x *= v; y *= v; return *this; }
point operator+(const point& p) const { return point(*this) += p; }
point operator-(const point& p) const { return point(*this) -= p; }
point operator*(long long v) const { return point(*this) *= v; }
long long dot(const point& p) const { return x * p.x + y * p.y; }
long long cross(const point& p) const { return x * p.y - y * p.x; }
string to_string() const {
return "(" + std::to_string(x) + ", " + std::to_string(y) + ")";
}
};
enum { ONLINE_FRONT = -2, CLOCKWISE, ON_SEGMENT, COUNTER_CLOCKWISE, ONLINE_BACK };
int ccw(const point& z, const point& a, const point& b) {
if ((a - z).cross(b - z) > 0) return COUNTER_CLOCKWISE;
if ((a - z).cross(b - z) < 0) return CLOCKWISE;
if ((a - z).dot(b - z) < 0) return ONLINE_BACK;
if ((z - a).dot(b - a) < 0) return ONLINE_FRONT;
return ON_SEGMENT;
}
vector<int> convex_hull(int n, const vector<point>& g) {
if (g == vector<point>(n, g[0])) {
return {0};
}
vector<int> ord(n);
for (int i = 0; i < n; i++) {
ord[i] = i;
}
sort(ord.begin(), ord.end(), [&](int a, int b) {
return g[a].y != g[b].y ? g[a].y < g[b].y : g[a].x < g[b].x;
});
vector<int> st;
for (int i = 0; i < 2; i++) {
int base = st.size();
for (int v0 : ord) {
while (int(st.size()) >= base + 2) {
int v1 = st[st.size() - 1];
int v2 = st[st.size() - 2];
int z = ccw(g[v0], g[v1], g[v2]);
if (z == CLOCKWISE) {
break;
}
st.pop_back();
}
st.push_back(v0);
}
st.pop_back();
reverse(ord.begin(), ord.end());
}
return st;
}
long long solve(int N, const vector<point>& P) {
// step #1. compute first layer
vector<int> s1 = convex_hull(N, P);
vector<bool> used(N, false);
for (int i : s1) {
used[i] = true;
}
if (used == vector<bool>(N, true)) {
return -1; // P is convex
}
// step #2. compute second layer
vector<point> Q;
for (int i = 0; i < N; i++) {
if (!used[i]) {
Q.push_back(P[i]);
}
}
vector<int> s2 = convex_hull(Q.size(), Q);
// step #3. calculate area
s1.push_back(s1[0]);
long long area = 0;
for (int i = 0; i < int(s1.size()) - 1; i++) {
area += P[s1[i]].cross(P[s1[i + 1]]);
}
// step #4. calculate answer
long long mindec = INF;
for (int i = 0; i < int(s1.size()) - 1; i++) {
point v = P[s1[i + 1]] - P[s1[i]];
auto comp = [&](int x, int y) {
return v.cross(Q[s2[x]] - P[s1[i]]) > v.cross(Q[s2[y]] - P[s1[i]]);
};
int a = 0, b = s2.size(), c = s2.size() * 2;
while (abs(c - a) > 2) {
if (abs(b - a) < abs(c - b)) {
swap(a, c);
}
int s = (a + b) / 2;
if (comp(s % s2.size(), b % s2.size())) {
a = s;
} else {
c = b;
b = s;
}
}
int target = b % s2.size();
long long reduce = v.cross(Q[s2[target]] - P[s1[i]]);
mindec = min(mindec, reduce);
}
return area - mindec;
}
int main() {
int T;
cin >> T;
for (int id = 1; id <= T; id++) {
int N;
cin >> N;
vector<point> P(N);
for (int i = 0; i < N; i++) {
cin >> P[i].x >> P[i].y;
}
long long ans = solve(N, P);
cout << ans << '\n';
}
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: 0ms
memory: 3556kb
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: 3636kb
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: 64ms
memory: 3936kb
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: 103ms
memory: 3808kb
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: 144ms
memory: 3844kb
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: 119ms
memory: 3868kb
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: 65ms
memory: 6200kb
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: 147ms
memory: 8256kb
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: 154ms
memory: 8028kb
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: 3796kb
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