#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define MAXN 1000005
ll a[MAXN];
int bit[MAXN];
map <ll,int> mp;
void update(int idx,int val)
{
while(idx < MAXN)
{
bit[idx] += val;
idx += idx&(-idx);
}
}
ll get(int idx)
{
ll ret = 0LL;
while(idx > 0)
{
ret += bit[idx];
idx -= idx&(-idx);
}
return ret;
}
ll get(int l,int r)
{
ll ret = get(r);
if(l > 0)ret -= get(l-1);
return ret;
}
vector <ll> all;
vector <ll> allz;
int main()
{
ios_base::sync_with_stdio(false);
int n;
cin >> n;
for(int i = 1; i <= n; i++)cin >> a[i];
int p;
cin >> p;
for(int i = 1; i <= n; i++)a[i]-=p,a[i]+=a[i-1];
allz.push_back(0);
for(int i = 1; i <= n; i++)allz.push_back(a[i]);
sort(allz.begin(),allz.end());
ll prev = -1e18;
for(auto x:allz)
{
if(x==prev)continue;
all.push_back(x);
prev=x;
}
ll ans = 0LL;
for(int i = 0; i <= n; i++)
{
int idx = lower_bound(all.begin(),all.end(),a[i])-all.begin();
idx++;
ans += 1LL*get(idx);
update(idx,1);
}
cout << ans;
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
640 KB |
Output is correct |
2 |
Correct |
3 ms |
640 KB |
Output is correct |
3 |
Correct |
3 ms |
640 KB |
Output is correct |
4 |
Correct |
444 ms |
29016 KB |
Output is correct |
5 |
Correct |
251 ms |
23252 KB |
Output is correct |
6 |
Correct |
357 ms |
27988 KB |
Output is correct |
7 |
Correct |
418 ms |
28372 KB |
Output is correct |
8 |
Correct |
333 ms |
26964 KB |
Output is correct |
9 |
Correct |
432 ms |
29524 KB |
Output is correct |
10 |
Correct |
370 ms |
28300 KB |
Output is correct |