#include "bits/stdc++.h"
using namespace std;
using ll = long long;
ll sum(ll l, ll r) {
// l^2 + ... + r^2
l--;
return r * (r + 1) / 2 - l * (l + 1) / 2;
return r * (r + 1) * (2 * r + 1) / 6 - l * (l + 1) * (2 * l + 1) / 6;
}
int brute(int n, vector<int> &a) {
int ans = 0;
for (int i = 0; i < n; i++) {
vector<int> cnt(n);
int mx = 0;
for (int j = i; j < n; j++) {
cnt[a[j]]++;
mx = max(mx, cnt[a[j]]);
if (2 * mx > (j - i + 1)) {
ans++;
}
}
}
return ans;
}
void solve() {
int n;
cin >> n;
map<int, int> mp;
vector<int> cnt, a(n);
{
for (int &x: a) {
cin >> x;
mp[x];
}
int z = 0;
for (auto &it: mp) {
it.second = z++;
}
cnt.assign(mp.size(), 0);
for (int &x: a) {
x = mp[x];
cnt[x]++;
}
}
vector<vector<int>> pos(mp.size());
for (int i = 0; i < n; i++) {
pos[a[i]].emplace_back(i);
}
int N = 3 * sqrt(n);
ll ans = 0;
for (int i = 0; i < mp.size(); i++) {
if (cnt[i] <= N) {
for (int l = 0; l < cnt[i]; l++) {
for (int r = l; r < cnt[i]; r++) {
int left = 0, right = n - 1, plus = r - l + 1;
int have = 2 * plus - (pos[i][r] - pos[i][l] + 1);
if (have <= 0) {
continue;
}
if (l > 0) {
left = pos[i][l - 1] + 1;
}
if (r + 1 < cnt[i]) {
right = pos[i][r + 1] - 1;
}
right = min(right, pos[i][r] + (have - 1));
left = max(left, pos[i][l] - (have - 1));
int right2 = left + (2 * plus - 1) - 1;
int left2 = right - (2 * plus - 1) + 1;
if (right2 < right) {
int x = pos[i][l] - left2 + 1;
ans += sum(x, right - right2 + x - 1);
} else {
right2 = right;
}
ans += (pos[i][l] - left + 1) * (right2 - pos[i][r] + 1);
}
}
} else {
vector<int> pref(n + 1), cs(2 * n + 1);
for (int j = 0; j < n; j++) {
pref[j + 1] = pref[j] + (a[j] == i ? 1 : -1);
}
for (int j = 0; j <= n; j++) {
pref[j] += n;
}
cs[pref[n]]++;
int now = 0;
for (int j = n - 1; j >= 0; j--) {
// count of k that pref[k] > pref[j] and k > j
if (pref[j] < pref[j + 1]) {
now += cs[pref[j + 1]];
} else {
now -= cs[pref[j]];
}
ans += now;
cs[pref[j]]++;
}
}
}
cout << ans;
}
int main() {
ios_base::sync_with_stdio(false);
cout.tie(nullptr);
cin.tie(nullptr);
int queries = 1;
#ifdef test_cases
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
cin >> queries;
#else
// cin >> queries;
#endif
for (int test_case = 1; test_case <= queries; test_case++) {
#ifdef test_cases
cout << "Test case: " << test_case << '\n';
#endif
solve();
cout << '\n';
}
}
Compilation message
Main.cpp: In function 'void solve()':
Main.cpp:55:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::map<int, int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
55 | for (int i = 0; i < mp.size(); i++) {
| ~~^~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
1 ms |
212 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
1 ms |
212 KB |
Output is correct |
7 |
Correct |
1 ms |
340 KB |
Output is correct |
8 |
Correct |
0 ms |
212 KB |
Output is correct |
9 |
Correct |
1 ms |
340 KB |
Output is correct |
10 |
Correct |
1 ms |
340 KB |
Output is correct |
11 |
Correct |
1 ms |
340 KB |
Output is correct |
12 |
Correct |
1 ms |
340 KB |
Output is correct |
13 |
Correct |
1 ms |
340 KB |
Output is correct |
14 |
Correct |
1 ms |
340 KB |
Output is correct |
15 |
Correct |
1 ms |
340 KB |
Output is correct |
16 |
Correct |
1 ms |
340 KB |
Output is correct |
17 |
Correct |
1 ms |
340 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
10 ms |
3052 KB |
Output is correct |
2 |
Correct |
15 ms |
3768 KB |
Output is correct |
3 |
Correct |
8 ms |
2364 KB |
Output is correct |
4 |
Correct |
14 ms |
3976 KB |
Output is correct |
5 |
Correct |
14 ms |
4168 KB |
Output is correct |
6 |
Correct |
15 ms |
4428 KB |
Output is correct |
7 |
Correct |
15 ms |
4428 KB |
Output is correct |
8 |
Correct |
15 ms |
4408 KB |
Output is correct |
9 |
Correct |
15 ms |
4428 KB |
Output is correct |
10 |
Correct |
15 ms |
4432 KB |
Output is correct |
11 |
Correct |
11 ms |
4320 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
1 ms |
212 KB |
Output is correct |
7 |
Correct |
1 ms |
340 KB |
Output is correct |
8 |
Correct |
0 ms |
212 KB |
Output is correct |
9 |
Correct |
1 ms |
340 KB |
Output is correct |
10 |
Correct |
1 ms |
340 KB |
Output is correct |
11 |
Correct |
1 ms |
340 KB |
Output is correct |
12 |
Correct |
1 ms |
340 KB |
Output is correct |
13 |
Correct |
1 ms |
340 KB |
Output is correct |
14 |
Correct |
1 ms |
340 KB |
Output is correct |
15 |
Correct |
1 ms |
340 KB |
Output is correct |
16 |
Correct |
1 ms |
340 KB |
Output is correct |
17 |
Correct |
1 ms |
340 KB |
Output is correct |
18 |
Correct |
10 ms |
3052 KB |
Output is correct |
19 |
Correct |
15 ms |
3768 KB |
Output is correct |
20 |
Correct |
8 ms |
2364 KB |
Output is correct |
21 |
Correct |
14 ms |
3976 KB |
Output is correct |
22 |
Correct |
14 ms |
4168 KB |
Output is correct |
23 |
Correct |
15 ms |
4428 KB |
Output is correct |
24 |
Correct |
15 ms |
4428 KB |
Output is correct |
25 |
Correct |
15 ms |
4408 KB |
Output is correct |
26 |
Correct |
15 ms |
4428 KB |
Output is correct |
27 |
Correct |
15 ms |
4432 KB |
Output is correct |
28 |
Correct |
11 ms |
4320 KB |
Output is correct |
29 |
Correct |
18 ms |
4304 KB |
Output is correct |
30 |
Correct |
18 ms |
4140 KB |
Output is correct |
31 |
Correct |
39 ms |
7308 KB |
Output is correct |
32 |
Correct |
106 ms |
13964 KB |
Output is correct |
33 |
Correct |
46 ms |
7884 KB |
Output is correct |
34 |
Correct |
43 ms |
7936 KB |
Output is correct |
35 |
Correct |
27 ms |
5588 KB |
Output is correct |
36 |
Correct |
19 ms |
3692 KB |
Output is correct |
37 |
Correct |
19 ms |
4268 KB |
Output is correct |
38 |
Correct |
18 ms |
4468 KB |
Output is correct |
39 |
Correct |
18 ms |
4304 KB |
Output is correct |
40 |
Correct |
18 ms |
4428 KB |
Output is correct |
41 |
Correct |
18 ms |
4304 KB |
Output is correct |
42 |
Correct |
18 ms |
4616 KB |
Output is correct |
43 |
Correct |
31 ms |
4784 KB |
Output is correct |
44 |
Correct |
32 ms |
4688 KB |
Output is correct |
45 |
Correct |
31 ms |
4692 KB |
Output is correct |
46 |
Correct |
36 ms |
4692 KB |
Output is correct |
47 |
Correct |
31 ms |
4692 KB |
Output is correct |
48 |
Correct |
83 ms |
4472 KB |
Output is correct |
49 |
Correct |
83 ms |
4452 KB |
Output is correct |
50 |
Correct |
67 ms |
4956 KB |
Output is correct |
51 |
Correct |
68 ms |
4968 KB |
Output is correct |
52 |
Correct |
47 ms |
2004 KB |
Output is correct |
53 |
Correct |
57 ms |
1968 KB |
Output is correct |
54 |
Correct |
72 ms |
2004 KB |
Output is correct |