| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 848546 |
2023-09-12T21:14:00 Z |
lovrot |
Tri (CEOI09_tri) |
C++17 |
|
137 ms |
24508 KB |
#include <cstdio>
#include <cassert>
#include <vector>
#include <algorithm>
#define X first
#define Y second
#define EB emplace_back
using namespace std;
typedef long long ll;
struct dot {
ll x, y;
dot() {}
dot(ll x, ll y) : x(x), y(y) {}
bool operator< (dot p) { return (p.x - x) * (-y) - (p.y - y) * (-x) > 0; }
ll operator* (dot p) { return p.x * x + p.y * y; }
};
ll ccw(dot a, dot b, dot c) { return (b.x - a.x) * (c.y - a.y) - (b.y - a.y) * (c.x - a.x); }
const int LOG = 17;
const int N = 1 << LOG;
dot D[N][2], INV[N];
int L[N], R[N], ANS[N];
vector<int> Q[2 * N], I[N];
vector<dot> CH, CIR;
int query(const dot &d, int lo, int hi) {
while(hi - lo > 1) {
int mi = (lo + hi) / 2;
if(CH[mi] * d < CH[mi + 1] * d) hi = mi;
else lo = mi;
}
return CH[lo] * d < CH[hi] * d ? lo : hi;
}
void fake() {
for(dot d : CIR) {
while(CH.size() > 1 && ccw(end(CH)[-2], end(CH)[-1], d) > 0) CH.pop_back();
CH.EB(d);
}
for(int i : Q[1])
if(ccw(D[i][1], D[i][0], CH[query(INV[i], 0, (int) CH.size() - 1)]) > 0) ANS[i] = 1;
}
void divcon(int lo, int hi, int x = 1) {
if(lo >= hi || Q[x].empty()) return;
if(lo + 1 == hi) {
for(int i : Q[x]) ANS[i] |= ccw(D[i][1], D[i][0], CIR[lo]) > 0;
return;
}
int mi = (lo + hi) / 2;
for(int i : Q[x]) {
if(R[i] < mi) Q[2 * x].EB(i);
else if(L[i] >= mi) Q[2 * x + 1].EB(i);
else I[L[i]].EB(i), I[R[i]].EB(i);
}
CH.clear();
for(int i = mi; i < hi; ++i) {
dot d = CIR[i];
while(CH.size() > 1 && ccw(end(CH)[-2], end(CH)[-1], d) > 0) CH.pop_back();
CH.EB(d);
for(int j : I[i])
if(ccw(D[j][1], D[j][0], CH[query(INV[j], 0, (int) CH.size() - 1)]) > 0) ANS[j] = 1;
}
CH.clear();
for(int i = mi - 1; i >= lo; --i) {
dot d = CIR[i];
while(CH.size() > 1 && ccw(end(CH)[-2], end(CH)[-1], d) < 0) CH.pop_back();
CH.EB(d);
for(int j : I[i])
if(ccw(D[j][1], D[j][0], CH[query(INV[j], 0, (int) CH.size() - 1)]) > 0) ANS[j] = 1;
}
for(int i = lo; i < hi; ++i) I[i].clear();
divcon(lo, mi, 2 * x);
divcon(mi, hi, 2 * x + 1);
}
int search(const dot &d) {
int lo = -1, hi = (int) CIR.size();
while(hi - lo > 1) {
int mi = (lo + hi) / 2;
if(CIR[mi] < d) lo = mi;
else hi = mi;
}
return hi;
}
int main() {
int n, m;
scanf("%d%d", &n, &m);
for(int i = 0; i < n; ++i) {
int x, y;
scanf("%d%d", &x, &y);
CIR.EB(dot(x, y));
}
sort(CIR.begin(), CIR.end());
// for(int i = 0; i < n; ++i) printf("%d %d\n", (int) CIR[i].x, (int) CIR[i].y);
for(int i = 0; i < m; ++i) {
int x, y, _x, _y;
scanf("%d%d%d%d", &x, &y, &_x, &_y);
D[i][0] = dot(x, y);
D[i][1] = dot(_x, _y);
INV[i] = dot(- (D[i][1].y - D[i][0].y), D[i][1].x - D[i][0].x);
L[i] = search(D[i][1]);
R[i] = search(D[i][0]) - 1;
// printf("%d: %d %d\n", i, L[i], R[i]);
if(L[i] <= R[i]) Q[1].EB(i);
}
divcon(0, n);
for(int i = 0; i < m; ++i) printf("%c\n", ANS[i] ? 'Y' : 'N');
return 0;
}
Compilation message
tri.cpp: In function 'int main()':
tri.cpp:95:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
95 | scanf("%d%d", &n, &m);
| ~~~~~^~~~~~~~~~~~~~~~
tri.cpp:98:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
98 | scanf("%d%d", &x, &y);
| ~~~~~^~~~~~~~~~~~~~~~
tri.cpp:105:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
105 | scanf("%d%d%d%d", &x, &y, &_x, &_y);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
13660 KB |
Output is correct |
| 2 |
Correct |
3 ms |
13660 KB |
Output is correct |
| 3 |
Correct |
25 ms |
16896 KB |
Output is correct |
| 4 |
Correct |
50 ms |
17828 KB |
Output is correct |
| 5 |
Correct |
98 ms |
20460 KB |
Output is correct |
| 6 |
Correct |
105 ms |
20088 KB |
Output is correct |
| 7 |
Correct |
130 ms |
21452 KB |
Output is correct |
| 8 |
Correct |
103 ms |
22308 KB |
Output is correct |
| 9 |
Correct |
121 ms |
23480 KB |
Output is correct |
| 10 |
Correct |
137 ms |
24508 KB |
Output is correct |
