#include <bits/stdc++.h>
using namespace std;
using ll = long long;
struct Ft {
vector<ll> bit;
int n;
void build(vector<ll> a) {
n = a.size()+2;
bit.assign(n+2, 0);
}
void update(int idx, int x) {
while(idx <= n) {
bit[idx] += x;
idx += idx & -idx;
}
}
ll sum(int idx) {
ll sum = 0;
while(idx > 0) {
sum += bit[idx];
idx -= idx & -idx;
}
return sum;
}
};
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
// freopen("test.in", "r", stdin);
int n;
cin >> n;
vector<int> a(n);
for(int& i : a) {
cin >> i;
}
int p;
cin >> p;
vector<ll> sum = {0};
for(int i : a) {
sum.push_back((ll) sum.back()+(i-p));
}
vector<ll> sums = sum;
sort(sums.begin(), sums.end());
Ft ft;
ft.build(sums);
ll ans = 0;
for(ll i : sum) {
int idx = lower_bound(sums.begin(), sums.end(), i) - sums.begin();
ans += ft.sum(idx+1);
ft.update(idx+1, +1);
}
cout << ans << "\n";
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
588 KB |
Output is correct |
2 |
Correct |
2 ms |
460 KB |
Output is correct |
3 |
Correct |
2 ms |
460 KB |
Output is correct |
4 |
Correct |
375 ms |
34396 KB |
Output is correct |
5 |
Correct |
194 ms |
19584 KB |
Output is correct |
6 |
Correct |
317 ms |
30508 KB |
Output is correct |
7 |
Correct |
316 ms |
31788 KB |
Output is correct |
8 |
Correct |
284 ms |
27616 KB |
Output is correct |
9 |
Correct |
371 ms |
35700 KB |
Output is correct |
10 |
Correct |
309 ms |
30952 KB |
Output is correct |