#include <bits/stdc++.h>
using namespace std;
const int N = 5e5 + 5;
struct point_t {
long long x, y;
point_t() {}
point_t(long long _x, long long _y) : x(_x), y(_y) {}
};
struct vector_t {
long long x, y;
vector_t() {}
vector_t(point_t a, point_t b) : x(b.x - a.x), y(b.y - a.y) {}
long long cross(vector_t o) {
return x * o.y - y * o.x;
}
};
bool cw(point_t a, point_t b, point_t c) {
vector_t ab(a, b), ac(a, c);
return ab.cross(ac) < 0;
}
int n;
int a[N];
point_t p[N];
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
cin >> n;
long long s = 0;
p[0] = point_t(0, 0);
for (int i = 1; i <= n; i++) {
cin >> a[i];
s += a[i];
p[i] = point_t(i, s);
}
vector<point_t> v;
v.push_back(p[0]);
v.push_back(p[1]);
for (int i = 2; i <= n; i++) {
while ((int) v.size() >= 2 && cw(v[(int) v.size() - 2], v.back(), p[i])) {
v.pop_back();
}
v.push_back(p[i]);
}
cout << (int) v.size() - 1 << '\n';
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
2396 KB |
Output is correct |
2 |
Correct |
0 ms |
2396 KB |
Output is correct |
3 |
Correct |
1 ms |
2396 KB |
Output is correct |
4 |
Correct |
0 ms |
2520 KB |
Output is correct |
5 |
Correct |
1 ms |
2396 KB |
Output is correct |
6 |
Incorrect |
1 ms |
2396 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
2396 KB |
Output is correct |
2 |
Correct |
0 ms |
2396 KB |
Output is correct |
3 |
Correct |
1 ms |
2396 KB |
Output is correct |
4 |
Correct |
0 ms |
2520 KB |
Output is correct |
5 |
Correct |
1 ms |
2396 KB |
Output is correct |
6 |
Incorrect |
1 ms |
2396 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
2396 KB |
Output is correct |
2 |
Correct |
0 ms |
2396 KB |
Output is correct |
3 |
Correct |
1 ms |
2396 KB |
Output is correct |
4 |
Correct |
0 ms |
2520 KB |
Output is correct |
5 |
Correct |
1 ms |
2396 KB |
Output is correct |
6 |
Incorrect |
1 ms |
2396 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
2396 KB |
Output is correct |
2 |
Correct |
0 ms |
2396 KB |
Output is correct |
3 |
Correct |
1 ms |
2396 KB |
Output is correct |
4 |
Correct |
0 ms |
2520 KB |
Output is correct |
5 |
Correct |
1 ms |
2396 KB |
Output is correct |
6 |
Incorrect |
1 ms |
2396 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
2396 KB |
Output is correct |
2 |
Correct |
0 ms |
2396 KB |
Output is correct |
3 |
Correct |
1 ms |
2396 KB |
Output is correct |
4 |
Correct |
0 ms |
2520 KB |
Output is correct |
5 |
Correct |
1 ms |
2396 KB |
Output is correct |
6 |
Incorrect |
1 ms |
2396 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |