#include<bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#define ll long long
using namespace std;
const int N = 1e6 + 10;
struct state
{
ll val;
int idx;
state() {};
state(ll val, int idx) : val(val), idx(idx) {};
bool operator < (const state & other) const
{
return this -> val < other.val;
}
};
struct FenWick
{
int MaxVal;
vector<int> tree;
FenWick()
{
MaxVal = 0;
};
void init(int n)
{
MaxVal = n;
tree.resize(n + 1, 0);
}
void Update(int idx, int val)
{
while(idx <= MaxVal)
{
tree[idx] += val;
idx += (idx & - idx);
}
}
int Query(int idx)
{
int s = 0;
while(idx > 0)
{
s += tree[idx];
idx -= (idx & - idx);
}
return s;
}
int Sum_to(int lhs, int rhs)
{
if(lhs > rhs) return 0;
return Query(rhs) - Query(lhs - 1);
}
};
int n;
ll limit;
ll s[N];
state a[N];
state memo[N];
ll res;
void pre_process()
{
for(int i = 1; i <= n; i++)
{
a[i] = state(s[i - 1] - limit * i + limit, i);
memo[i] = state(s[i] - limit * i, i);
}
sort(a + 1, a + 1 + n);
sort(memo + 1, memo + 1 + n);
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
// freopen("Vudu.inp", "r", stdin);
// freopen("Vudu.out", "w", stdout);
cin >> n;
for(int i = 1; i <= n; i++)
{
int a; cin >> a;
s[i] = s[i - 1] + a;
}
cin >> limit;
pre_process();
FenWick bit;
bit.init(n);
for(int i = 1, j = 1; i <= n; i++)
{
while(j <= n && a[j].val <= memo[i].val) bit.Update(a[j].idx, 1), j++;
res += bit.Query(memo[i].idx);
}
cout << res;
return 0;
}
/// Code by vuavisao
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
724 KB |
Output is correct |
2 |
Correct |
2 ms |
596 KB |
Output is correct |
3 |
Correct |
3 ms |
596 KB |
Output is correct |
4 |
Correct |
387 ms |
51188 KB |
Output is correct |
5 |
Correct |
223 ms |
29076 KB |
Output is correct |
6 |
Correct |
330 ms |
45424 KB |
Output is correct |
7 |
Correct |
331 ms |
47244 KB |
Output is correct |
8 |
Correct |
281 ms |
40936 KB |
Output is correct |
9 |
Correct |
380 ms |
52940 KB |
Output is correct |
10 |
Correct |
346 ms |
45984 KB |
Output is correct |