Submission #1020559

#	Time	Username	Problem	Language	Result	Execution time	Memory
1020559		BuzzyBeez	Untitled (POI11_rot)	C++17	72 / 100	206 ms	65536 KiB

Main

#include <bits/stdc++.h>
using namespace std;

const int N = 4e5;

int a[N + 8];
int adj[N + 8][2];
set<int> _list[N + 8];
int sz[N + 8];

int n, tmp, id = 1, x;
void input() {
	cin >> x;
	if (x) {_list[id].insert(x); ++sz[id]; a[id] = x; return;}
	int t = id;
	adj[t][0] = id + 1;
	++id; input();
	adj[t][1] = id + 1;
	++id; input();
}

void DFS_sz(int u, int p) {
	if (adj[u][0] == 0) return;
	DFS_sz(adj[u][0], u); sz[u] += sz[adj[u][0]];
	DFS_sz(adj[u][1], u); sz[u] += sz[adj[u][1]];
}

struct Binary_Indexed_Tree {
	vector<int> BIT;
	
	Binary_Indexed_Tree() {BIT.assign(N / 2 + 8, 0);}
	
	int pt;
	void update(int u, int v) {
		pt = u;
		while (pt <= N / 2) {
			BIT[pt] += v;
			pt += pt & -pt;
		}
	}
	
	int res;
	int pf(int p) {
		if (p <= 0) return 0;
		res = 0; pt = p;
		while (pt) {
			res += BIT[pt];
			pt -= pt & -pt;
		}
		return res;
	}
	
	int range(int l, int r) {
		if (l > r) return 0;
		return pf(r) - pf(l - 1);
	}
} tree;

int costLR, costRL;
long long DFS(int u, int p) {
	long long res = 0;
	if (sz[u] > 1) { 
		int L = adj[u][0], R = adj[u][1];
		if (sz[L] < sz[R]) swap(L, R);
		// cout << u << " -> " << R << endl;
		res += DFS(R, u);
		for (int item : _list[R]) tree.update(item, -1);
		// cout << u << " -> " << L << endl;
		res += DFS(L, u);
		costLR = costRL = 0;
		for (int item : _list[R]) costLR += tree.range(item + 1, n), costRL += tree.range(1, item - 1);
		res += min(costLR, costRL);
		for (int item : _list[R]) tree.update(item, +1);
		for (int v : {L, R}) {
			if (_list[u].size() < _list[v].size()) swap(_list[u], _list[v]);
			for (int item : _list[v]) _list[u].insert(item);
		}
	}
	if (a[u]) tree.update(a[u], +1);
	return res;
}

signed main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	cin >> n; input();
	DFS_sz(1, 0); cout << DFS(1, 0);
}

• Subtask 1: 9 / 9
• Subtask 2: 9 / 9
• Subtask 3: 9 / 9
• Subtask 4: 9 / 9
• Subtask 5: 9 / 9
• Subtask 6: 9 / 9
• Subtask 7: 9 / 9
• Subtask 8: 9 / 9
• Subtask 9: 0 / 9
• Subtask 10: 0 / 9
• Subtask 11: 0 / 10