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Submission #667176

# Submission time Handle Problem Language Result Execution time Memory
667176 2022-11-30T16:04:15 Z Kahou Love Polygon (BOI18_polygon) C++14
100 / 100
 116 ms 22936 KB 
#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define endl '\n'
#define mk make_pair
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int N = 1e5 + 50;
int n, dp[N][2], dp2[N][2], vis[N], mark[N], t;
pll e[N];
vector<int> pth;
vector<int> vc[N];
vector<int> adj[N];

void dfs1(int u, int p) {
	vis[u] = 1;
	pth.push_back(u);
	bool flg = 0;
	bool flg2 = 0;
	for (int v:adj[u]) {
		if (!flg && v == p) {
			flg = 1;
			continue;
		}
		if (!vis[v]) {
			dfs1(v, u);
		}
		else if (!flg2 && vis[v] == 1) {
			flg2 = 1;
			int pt = (int)pth.size()-1;
			while (pth[pt] != v) {
				vc[t].push_back(pth[pt]);
				mark[pth[pt]] = 1;
				pt--;
			}
			vc[t].push_back(pth[pt]);
			mark[pth[pt]] = 1;
		}
	}
	pth.pop_back();
	vis[u] = 2;
}

void dfs2(int u, int p) {
	for (int v:adj[u]) {
		if (v == p || mark[v]) continue;
		dfs2(v, u);
		dp[u][1] += dp[v][0];
	}
	dp[u][0] = dp[u][1];
	for (int v:adj[u]) {
		if (v == p || mark[v]) continue;
		dp[u][0] = max(dp[u][0], dp[u][1] - dp[v][0] + dp[v][1] + 1);
	}
}

void solve() {
	cin >> n;
	for (int i = 1; i <= n; i++) {
		string s, t;
		cin >> s >> t;
		ll u = 0, v = 0;
		for (char c:s) {
			u = u*27 + (c-'a'+1);
		}
		for (char c:t) {
			v = v*27 + (c-'a'+1);
		}
		e[i] = {u, v};
	}
	if (n&1) {
		cout << -1 << endl;
		return;
	}
	sort(e+1, e+n+1);
	for (int u = 1; u <= n; u++) {
		int v = lower_bound(e+1, e+n+1, mk(e[u].S, 0ll))-e;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	for (int u = 1; u <= n; u++) {
		if (!vis[u]) {
			t++;
			dfs1(u, 0);
		}
	}
	int ans = 0;
	for (int x = 1; x <= t; x++) {
		for (int u:vc[x]) {
			dfs2(u, 0);
		}
		if (vc[x].size() == 1) {
			ans += dp[vc[x][0]][0];
			continue;
		}
		if (vc[x].size() == 2) {
			int u = vc[x][0], v = vc[x][1];
			ans += max(dp[u][1] + dp[v][1] + 2, dp[u][0] + dp[v][0]);
			continue;
		}

		vc[x].push_back(vc[x][0]);
		int s = vc[x].size();
		int mx = 0;

		dp2[vc[x][0]][0] = 0;
		dp2[vc[x][0]][1] = -1e9;
		for (int i = 1; i < s; i++) {
			int u = vc[x][i];
			int v = vc[x][i-1];
			dp2[u][0] = max(dp2[v][0] + dp[v][0], dp2[v][1] + dp[v][1]);
			dp2[u][1] = dp2[v][0] + dp[v][1] + 1;
		}
		mx = max(mx, dp2[vc[x].back()][0]);

		dp2[vc[x][0]][0] = -1e9;
		dp2[vc[x][0]][1] = 0;
		for (int i = 1; i < s; i++) {
			int u = vc[x][i];
			int v = vc[x][i-1];
			dp2[u][0] = max(dp2[v][0] + dp[v][0], dp2[v][1] + dp[v][1]);
			dp2[u][1] = dp2[v][0] + dp[v][1] + 1;
		}
		mx = max(mx, dp2[vc[x].back()][1]);
		ans += mx;
	}
	cout << n-ans << endl;
}

int main() {
	ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	solve();
	return 0;
}

Subtask #1
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 3 ms 5024 KB Output is correct
6 Correct 3 ms 5032 KB Output is correct
7 Correct 4 ms 5036 KB Output is correct
8 Correct 3 ms 5024 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 2 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 3 ms 4948 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 5024 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5032 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 4 ms 4992 KB Output is correct
4 Correct 83 ms 21820 KB Output is correct
5 Correct 75 ms 15140 KB Output is correct
6 Correct 99 ms 22908 KB Output is correct
7 Correct 19 ms 8704 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 85 ms 13408 KB Output is correct
2 Correct 80 ms 14924 KB Output is correct
3 Correct 50 ms 16532 KB Output is correct
4 Correct 20 ms 8740 KB Output is correct
5 Correct 116 ms 20716 KB Output is correct
6 Correct 89 ms 13064 KB Output is correct
7 Correct 68 ms 13528 KB Output is correct
8 Correct 61 ms 14916 KB Output is correct
9 Correct 62 ms 13340 KB Output is correct
10 Correct 38 ms 13340 KB Output is correct
11 Correct 3 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 3 ms 5036 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct

Subtask #4
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 3 ms 5024 KB Output is correct
6 Correct 3 ms 5032 KB Output is correct
7 Correct 4 ms 5036 KB Output is correct
8 Correct 3 ms 5024 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 2 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 3 ms 4948 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 5024 KB Output is correct
16 Correct 4 ms 5032 KB Output is correct
17 Correct 3 ms 4948 KB Output is correct
18 Correct 4 ms 4992 KB Output is correct
19 Correct 83 ms 21820 KB Output is correct
20 Correct 75 ms 15140 KB Output is correct
21 Correct 99 ms 22908 KB Output is correct
22 Correct 19 ms 8704 KB Output is correct
23 Correct 85 ms 13408 KB Output is correct
24 Correct 80 ms 14924 KB Output is correct
25 Correct 50 ms 16532 KB Output is correct
26 Correct 20 ms 8740 KB Output is correct
27 Correct 116 ms 20716 KB Output is correct
28 Correct 89 ms 13064 KB Output is correct
29 Correct 68 ms 13528 KB Output is correct
30 Correct 61 ms 14916 KB Output is correct
31 Correct 62 ms 13340 KB Output is correct
32 Correct 38 ms 13340 KB Output is correct
33 Correct 3 ms 4948 KB Output is correct
34 Correct 3 ms 4948 KB Output is correct
35 Correct 3 ms 5036 KB Output is correct
36 Correct 3 ms 4948 KB Output is correct
37 Correct 90 ms 14272 KB Output is correct
38 Correct 77 ms 15776 KB Output is correct
39 Correct 72 ms 14496 KB Output is correct
40 Correct 66 ms 13672 KB Output is correct
41 Correct 74 ms 13576 KB Output is correct
42 Correct 75 ms 13992 KB Output is correct
43 Correct 88 ms 14192 KB Output is correct
44 Correct 75 ms 14260 KB Output is correct
45 Correct 71 ms 14204 KB Output is correct
46 Correct 71 ms 14152 KB Output is correct
47 Correct 68 ms 14508 KB Output is correct
48 Correct 78 ms 13424 KB Output is correct
49 Correct 77 ms 14888 KB Output is correct
50 Correct 45 ms 16528 KB Output is correct
51 Correct 20 ms 8672 KB Output is correct
52 Correct 91 ms 20616 KB Output is correct
53 Correct 87 ms 13164 KB Output is correct
54 Correct 72 ms 13456 KB Output is correct
55 Correct 63 ms 14908 KB Output is correct
56 Correct 61 ms 13344 KB Output is correct
57 Correct 34 ms 13388 KB Output is correct
58 Correct 3 ms 5032 KB Output is correct
59 Correct 4 ms 5004 KB Output is correct
60 Correct 3 ms 4948 KB Output is correct
61 Correct 3 ms 4948 KB Output is correct
62 Correct 3 ms 4948 KB Output is correct
63 Correct 3 ms 4948 KB Output is correct
64 Correct 3 ms 4948 KB Output is correct
65 Correct 104 ms 21796 KB Output is correct
66 Correct 86 ms 15184 KB Output is correct
67 Correct 106 ms 22936 KB Output is correct
68 Correct 18 ms 8652 KB Output is correct
69 Correct 3 ms 4948 KB Output is correct
70 Correct 3 ms 5036 KB Output is correct
71 Correct 3 ms 5048 KB Output is correct
72 Correct 4 ms 4948 KB Output is correct
73 Correct 4 ms 5028 KB Output is correct
74 Correct 4 ms 5028 KB Output is correct
75 Correct 4 ms 4948 KB Output is correct
76 Correct 3 ms 4948 KB Output is correct
77 Correct 3 ms 4948 KB Output is correct
78 Correct 3 ms 4948 KB Output is correct
79 Correct 3 ms 4948 KB Output is correct
80 Correct 3 ms 4948 KB Output is correct
81 Correct 3 ms 4948 KB Output is correct
82 Correct 3 ms 5032 KB Output is correct
83 Correct 3 ms 4948 KB Output is correct