#include <bits/stdc++.h>
using namespace std;
const int MAXN = 500000;
struct BIT {
vector<int> tree;
int n;
void init(int _n) {
n = _n;
tree.assign(n+1,0);
}
void update(int pos,int val) {
for (;pos <= n;pos += pos & -pos) tree[pos] += val;
}
int query(int pos) {
int sum = 0;
for (;pos > 0;pos -= pos & -pos) sum += tree[pos];
return sum;
}
int query(int l,int r) {
if (l > r) return 0;
return query(r) - query(l-1);
}
} tree;
vector<int> adj[MAXN+1];
stack<pair<int,int>> st;
vector<int> ch[MAXN+1];
int val[MAXN+1];
int sz[MAXN+1];
int n,m;
int cnt;
long long ans = 0;
int cal_sz(int u) {
if (adj[u].size() == 0) return sz[u] = 1;
sz[u] += cal_sz(adj[u][0]);
sz[u] += cal_sz(adj[u][1]);
return sz[u];
}
void dfs(int u,int keep) {
if (adj[u].size() == 0) {
ch[u].push_back(val[u]);
if (keep) tree.update(val[u],1);
return;
}
int lt = adj[u][0], rt = adj[u][1];
long long tmp = 0;
if (sz[lt] < sz[rt]) {
dfs(lt,0);
dfs(rt,1);
ch[u].swap(ch[rt]);
for (int i=0;i<ch[lt].size();i++) {
int v = ch[lt][i];
ch[u].push_back(v);
// cerr << u << ' ' << v << '\n';
tmp += tree.query(1,v-1);
}
for (int i=0;i<ch[lt].size();i++) {
tree.update(ch[lt][i],1);
}
}
else {
dfs(rt,0);
dfs(lt,1);
ch[u].swap(ch[lt]);
for (int i=0;i<ch[rt].size();i++) {
int v = ch[rt][i];
// cerr << u << ' ' << v << '\n';
ch[u].push_back(v);
tmp += tree.query(v+1,m);
}
for (int i=0;i<ch[rt].size();i++) {
tree.update(ch[rt][i],1);
}
}
tmp = min(tmp,1ll * sz[lt] * sz[rt] - tmp);
// cerr << u << ' ' << tmp << '\n';
// cerr << tree.query(1,m) << '\n';
ans += tmp;
if (!keep) {
for (int i=0;i<ch[u].size();i++) {
tree.update(ch[u][i],-1);
}
}
}
int main() {
cin.tie(0) -> sync_with_stdio(0);
cin >> m;
tree.init(m);
for (n=1;;n++) {
cin >> val[n];
if (st.size()) adj[st.top().first].push_back(n);
if (val[n] != 0) cnt++;
if (val[n] != 0 && st.top().second == 2) st.pop();
else if (val[n] != 0) st.top().second++;
else {
st.push({n,1});
}
if (cnt == m) break;
}
cal_sz(1);
// dfs(1,1);
cout << ans;
return 0;
}
Compilation message
rot.cpp: In function 'void dfs(int, int)':
rot.cpp:56:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
56 | for (int i=0;i<ch[lt].size();i++) {
| ~^~~~~~~~~~~~~~
rot.cpp:62:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
62 | for (int i=0;i<ch[lt].size();i++) {
| ~^~~~~~~~~~~~~~
rot.cpp:70:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
70 | for (int i=0;i<ch[rt].size();i++) {
| ~^~~~~~~~~~~~~~
rot.cpp:76:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
76 | for (int i=0;i<ch[rt].size();i++) {
| ~^~~~~~~~~~~~~~
rot.cpp:85:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
85 | for (int i=0;i<ch[u].size();i++) {
| ~^~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
5 ms |
27472 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
5 ms |
27472 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
5 ms |
27472 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
6 ms |
27728 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
7 ms |
27984 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
15 ms |
29520 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
19 ms |
31056 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
36 ms |
32720 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
34 ms |
34460 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
48 ms |
36172 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
42 ms |
36440 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |