#include<bits/stdc++.h>
using namespace std;
#define cerr while(0) cerr
#define ld double
#define x first
#define y second
#define vt vector
#define pb push_back
#define wassert(x) do { if(not (x)) { cout << -329032 << '\n'; exit(0); } } while(0)
const int maxn = 1e5+5;
int K,M;
struct line {
ld m;
ld c;
line() {}
line(ld a, ld b) {
m = a;
c = b;
}
};
ld interx(line a, line b) {
ld res = (ld)(b.c - a.c) / (ld)(a.m - b.m);
return res;
}
line alns[maxn];
struct cht {
bool PREPPED = 0;
vt<int> emb;
vt<pair<ld, int>> sta;
void push(int lne) {
if(PREPPED) {
cerr << "Tried inserting on query-only mode!\n";
// assert(1 == 2);
}
emb.push_back(lne);
}
bool bye(pair<ld, int> g, line h) {
ld cut = g.first;
if(interx(alns[g.second], h) <= cut) {
return true;
}
return false;
}
void solve() {
//BUG: without the capture clause it is undefined behaviour?
sort(begin(emb), end(emb), [&](int a, int b) {if(alns[a].m == alns[b].m) return alns[a].c > alns[b].c; else return alns[a].m > alns[b].m; }); //BUG: Did not account for equal gradients
for(int c: emb) {
line curr = alns[c];
while(sta.size() and (alns[sta.back().second].m == curr.m or bye(sta.back(), curr))) {
sta.pop_back();
}
ld ccut = -1e18;
if(sta.size()) {
ccut = interx(curr, alns[sta.back().second]);
}
if(ccut <= 1e18) sta.push_back({ccut, c});
}
// cerr << "Yep done\n";
emb.clear();
}
bool query(ld x, ld maxy) {
if(not PREPPED) { //BUG: Solve needs to always be before stack condition
cerr << "Query-only mode activated\n";
solve();
PREPPED = true;
}
cerr << "I can reach this\n";
if(sta.empty()) { //BUG: should've checked empty case
return false;
}
auto lb = upper_bound(begin(sta), end(sta), x,
[](ld q, pair<ld, int> a) {
return q < a.first;
}
); //BUG: Upper bound was so much more weird compared to lower bound
//Otherwise code was good, trust your code.
// assert(lb != begin(sta));
lb = prev(lb);
line now = alns[lb->second];
ld lhs = (now.m * (ld)x + now.c);
return lhs <= (ld)maxy;
}
};
struct rational {
int p, q;
rational() {}
rational(int a, int b) {
p = a, q = b;
}
friend bool operator==(rational a, rational x) {
if(x.q == a.q and a.q == 0) {
return true;
} else if((x.q == 0 and a.q != 0) or (x.q != 0 and a.q == 0)) {
return false;
}
long long lhs = a.p * x.q;
long long rhs = a.q * x.p;
return lhs == rhs;
}
friend bool operator<(rational a, rational x) {
// assert(a.p >= 0 and a.q >= 0);
// assert(x.p >= 0 and x.q >= 0);
if(a.q == 0) return false;
if(x.q == 0) return true;
long long lhs = 1ll * a.p * x.q;
long long rhs = 1ll * a.q * x.p;
return lhs < rhs;
}
};
cht st[4*maxn];
bool seg_query(int x, int tl, int tr, int l, int r, ld m, ld b) {
wassert(x < 4 * maxn);
if(tl == l and tr == r) { //BUG: l == r instead of tl == l and tr == r
return st[x].query(m, b);
}
// assert(tl <= l and r <= tr);
int tm = (tl+tr)/2;
bool res = 0;
if(l <= tm) {
res = res or seg_query(x*2, tl, tm, l, min(tm,r), m, b); //BUG: should be l, min(tm,r)
}
if(tm < r) {
res = res or seg_query(x*2+1, tm+1, tr, max(tm+1,l), r, m, b); //BUG: should be max(tm+1,l), r
}
return res;
}
void seg_upd(int x, int tl, int tr, int pseu, int lne) {
wassert(x < 4 * maxn);
if(tl == tr) {
st[x].push(lne);
return;
}
int tm = (tl+tr)/2;
st[x].push(lne);
if(pseu <= tm) {
seg_upd(x*2, tl, tm, pseu, lne);
} else {
seg_upd(x*2+1, tm+1, tr, pseu, lne);
}
}
// struct seg {
// int tl, tr;
// seg *lc, *rc;
// cht db;
// bool has_child = 0;
// seg() {}
// seg(int a, int b) {
// tl = a, tr = b;
// }
// void split() {
// if(has_child or tl == tr) return;
// has_child = true;
// int tm = (tl+tr)/2;
// lc = new seg(tl, tm);
// rc = new seg(tm+1, tr);
// }
// bool query(int l, int r, ld m, ld b) {
// }
// void upd(int pseu, line u) {
// }
// };
pair<ld, ld> qs[maxn];
pair<int, int> points[maxn];
bool ans[maxn];
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> K >> M;
// vector<pair<rational, int>> mps; //object id
vt<rational> cdnat;
for(int i = 1; i <= K; i++) {
int xp, yp;
cin >> xp >> yp;
// cerr << (rational(1,1) == rational(2,2)) << '\n';
// cht.push(line(-xp, yp));
cdnat.pb(rational(yp, xp));
points[i] = {xp, yp};
}
int ptr = 0;
int roll = 1;
sort(begin(cdnat), end(cdnat)); //upd roll = cdnat size
unique(begin(cdnat), end(cdnat));
map<rational, int> compy;
for(int g = 0; g < cdnat.size(); g++) {
rational i = cdnat[g];
compy[i] = g+1;
}
roll = cdnat.size() + 1;
// cht.solve();
for(int i = 1; i <= K; i++) {
int xp = points[i].x, yp = points[i].y;
//REMEMBER: (-xp, yp) for line
alns[i] = line(-xp, yp);
seg_upd(1, 1, roll-1, compy[rational(yp, xp)], i);
}
for(int g = 1; g <= M; g++) { //Lines as queries: need qran[g] = something
int x1, y1, x2, y2; cin >> x1 >> y1 >> x2 >> y2;
rational lo (y1, x1), hi (y2, x2);
if(hi < lo) swap(lo, hi);
ld m = ((ld)(y2 - y1)) / ((ld)(x2 - x1));
ld b = -m * (ld)x1 + (ld)y1;
auto lef = compy.lower_bound(lo);
auto erig = compy.upper_bound(hi);
if(lef == compy.end() or erig == compy.begin()) {
cout << "N\n";
} else {
int ql = lef->second, qr = prev(erig)->second;
bool res = seg_query(1,1,roll-1,ql,qr,m,b);
if(res) {
cout << "Y\n";
} else {
cout << "N\n";
}
}
// mps.push_back({lo, g+K});
// mps.push_back({hi, g+K});
// cerr << m << ' ' << b << '\n';
// bool res = cht.query(m, b);
// qs[g] = {m, b};
}
//reduce memory: store
// sort(begin(mps), end(mps), [](pair<rational, int> a, pair<rational,int> b) { return a.x < b.x; });
// while(ptr < mps.size()) {
// vector<int> these;
// rational cur = mps[ptr].x;
// while(ptr < mps.size() and mps[ptr].x == cur) {
// these.push_back(mps[ptr].y);
// ptr++;
// }
// for(int it : these) {
// if(it <= K) {
// linp[it] = roll;
// } else {
// //AVOIDED BUG: it -= K;
// it -= K;
// if(qran[it].x == 0) {
// qran[it].x = roll;
// } else {
// qran[it].y = roll;
// }
// }
// }
// roll++;
// }
// seg* root = new seg(1, roll-1);
// free(points);
// free(linp);
// for(int g = 1; g <= M; g++) {
// int lef = compy[]
// ans[g] = seg_query(1, 1, roll-1, qran[g].x, qran[g].y, qs[g].x, qs[g].y);
// }
// for(int i = 1; i <= M; i++) {
// if(ans[i]) {
// cout << "Y\n";
// } else {
// cout << "N\n";
// }
// }
}
Compilation message
tri.cpp: In function 'int main()':
tri.cpp:188:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<rational>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
188 | for(int g = 0; g < cdnat.size(); g++) {
| ~~^~~~~~~~~~~~~~
tri.cpp:183:9: warning: unused variable 'ptr' [-Wunused-variable]
183 | int ptr = 0;
| ^~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
5 ms |
23132 KB |
Output is correct |
| 2 |
Correct |
6 ms |
23132 KB |
Output is correct |
| 3 |
Correct |
49 ms |
30672 KB |
Output is correct |
| 4 |
Correct |
80 ms |
36052 KB |
Output is correct |
| 5 |
Correct |
192 ms |
47824 KB |
Output is correct |
| 6 |
Correct |
252 ms |
47564 KB |
Output is correct |
| 7 |
Correct |
335 ms |
52872 KB |
Output is correct |
| 8 |
Correct |
259 ms |
57572 KB |
Output is correct |
| 9 |
Correct |
294 ms |
60368 KB |
Output is correct |
| 10 |
Correct |
357 ms |
63320 KB |
Output is correct |
