#include <bits/stdc++.h>
#define sz(x) ((int)x.size())
#define all(x) x.begin(),x.end()
#define PB push_back
using namespace std;
typedef long long ll;
const int N = 1000100;
vector<ll> vc;
int n, a[N], p, fen[N];
ll pf[N], ans = 0;
void update(int x){
for (; x < sz(vc); x = (x | (x + 1)))
fen[x]++;
}
int sum(int x){
int res = 0;
for (; x >= 0; x = (x & (x + 1)) - 1)
res += fen[x];
return res;
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0);
#ifdef _LOCAL
freopen("in.txt","r",stdin);
#endif // _LOCAL
cin >> n;
for (int i = 1; i <= n; i++)
cin >> a[i];
cin >> p;
pf[0] = 0;
vc.PB(0);
for (int i = 1; i <= n; i++){
pf[i] = pf[i - 1] + ll(a[i]) - ll(p);
vc.PB(pf[i]);
}
sort(all(vc));
vc.resize(unique(all(vc)) - vc.begin());
update(lower_bound(all(vc), pf[0]) - vc.begin());
for (int i = 1; i <= n; i++){
int ps = lower_bound(all(vc), pf[i]) - vc.begin();
ans += sum(ps);
update(ps);
}
cout << ans;
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
640 KB |
Output is correct |
2 |
Correct |
2 ms |
640 KB |
Output is correct |
3 |
Correct |
2 ms |
512 KB |
Output is correct |
4 |
Correct |
373 ms |
32800 KB |
Output is correct |
5 |
Correct |
213 ms |
20200 KB |
Output is correct |
6 |
Correct |
331 ms |
28884 KB |
Output is correct |
7 |
Correct |
341 ms |
30040 KB |
Output is correct |
8 |
Correct |
302 ms |
26068 KB |
Output is correct |
9 |
Correct |
401 ms |
33616 KB |
Output is correct |
10 |
Correct |
337 ms |
29268 KB |
Output is correct |