#include <bits/stdc++.h>
const int MAX_N = 100000;
struct Fraction {
int a, b;
Fraction() {
a = 0;
b = 1;
}
Fraction(int _a, int _b) {
a = _a;
b = _b;
if(b < 0) {
a = -a;
b = -b;
}
}
bool operator== (const Fraction x) const {
return (long long)a * x.b == (long long)b * x.a;
}
bool operator< (const Fraction x) const {
return (long long)a * x.b < b * x.a;
}
};
struct Point {
int x, y;
Fraction slope;
} points[MAX_N];
bool marked[MAX_N];
static inline long long detarea(int a, int b) {
return (long long)points[a].x * points[b].y - (long long)points[a].y * points[b].x;
}
static inline long long quadarea(int a, int b, int c, int d) {
return detarea(a, b) + detarea(b, c) + detarea(c, d) + detarea(d, a);
}
struct Segment {
int a, b;
bool operator< (const Segment x) const {
return quadarea(a, b, x.b, x.a) > 0;
}
} segments[MAX_N];
struct Event {
Fraction t;
int type, segmentId;
};
bool cmp(Event a, Event b) {
return a.t < b.t || (a.t == b.t && a.type < b.type);
}
int main() {
int N;
scanf("%d", &N);
for(int i = 0; i < N; ++i) {
scanf("%d%d", &points[i].x, &points[i].y);
points[i].slope = Fraction(points[i].y, points[i].x);
segments[i] = {i, (i + 1) % N};
}
std::vector<Event> ev;
for(int i = 0; i < N; ++i) {
if(points[segments[i].b].slope < points[segments[i].a].slope)
std::swap(segments[i].a, segments[i].b);
else if(points[segments[i].b].slope == points[segments[i].a].slope &&
points[segments[i].b].x > points[segments[i].a].x)
std::swap(segments[i].a, segments[i].b);
ev.push_back({points[segments[i].a].slope, 0, i});
ev.push_back({points[segments[i].b].slope, 2, i});
ev.push_back({points[i].slope, 1, i});
}
std::sort(ev.begin(), ev.end(), cmp);
std::set<Segment> segs;
for(int i = 0; i < 3 * N; ++i) {
if(ev[i].type == 0)
segs.insert(segments[ev[i].segmentId]);
else if(ev[i].type == 2)
segs.erase(segments[ev[i].segmentId]);
else {
Segment firstseg = *segs.rbegin();
if(points[firstseg.a].slope == points[firstseg.b].slope)
marked[ev[i].segmentId] = (ev[i].segmentId == firstseg.a);
else
marked[ev[i].segmentId] = (ev[i].segmentId == firstseg.a ||
ev[i].segmentId == firstseg.b);
}
}
int res = 0;
for(int i = 0; i < N; ++i)
if(marked[i])
++res;
printf("%d\n", res);
for(int i = 0; i < N; ++i)
if(marked[i])
printf("%d ", i + 1);
return 0;
}
Compilation message
circuit.cpp: In function 'int main()':
circuit.cpp:64:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &N);
~~~~~^~~~~~~~~~
circuit.cpp:66:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &points[i].x, &points[i].y);
~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
2 ms |
1920 KB |
Output isn't correct |
2 |
Runtime error |
4 ms |
3840 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
3 |
Runtime error |
6 ms |
4220 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
4 |
Correct |
6 ms |
2304 KB |
Output is correct |
5 |
Incorrect |
10 ms |
2936 KB |
Output isn't correct |
6 |
Incorrect |
10 ms |
2936 KB |
Output isn't correct |
7 |
Incorrect |
19 ms |
3576 KB |
Output isn't correct |
8 |
Runtime error |
9 ms |
4856 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
9 |
Correct |
15 ms |
2684 KB |
Output is correct |
10 |
Incorrect |
11 ms |
2936 KB |
Output isn't correct |
11 |
Incorrect |
11 ms |
3320 KB |
Output isn't correct |
12 |
Correct |
18 ms |
3448 KB |
Output is correct |
13 |
Incorrect |
33 ms |
4724 KB |
Output isn't correct |
14 |
Runtime error |
43 ms |
8804 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
15 |
Runtime error |
54 ms |
10204 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
16 |
Incorrect |
84 ms |
12260 KB |
Output isn't correct |
17 |
Execution timed out |
113 ms |
12516 KB |
Time limit exceeded |
18 |
Execution timed out |
33 ms |
4088 KB |
Time limit exceeded (wall clock) |
19 |
Execution timed out |
30 ms |
4096 KB |
Time limit exceeded (wall clock) |
20 |
Execution timed out |
33 ms |
4224 KB |
Time limit exceeded (wall clock) |