Submission #840535

# Submission time Handle Problem Language Result Execution time Memory
840535 2023-08-31T13:33:25 Z happypotato Longest Trip (IOI23_longesttrip) C++17
60 / 100
286 ms 728 KB
#include "longesttrip.h"

#include <bits/stdc++.h>
#pragma GCC optimize("O2")
using namespace std;
// #define int long long // remove when necessary
#define pii pair<int, int>
#define ff first
#define ss second
#define pb push_back
#define ll long long
const int mxN = 256;
vector<int> adj[mxN];
vector<int> grp[mxN];
int conn[mxN][mxN];
bool con(int x, int y) {
	if (conn[x][y] != -1) return conn[x][y];
	return (conn[x][y] = conn[y][x] = are_connected({x}, {y}));
}
int n;
int dsupp[mxN];
vector<int> nxt[mxN];
bool vis[mxN];
void resetvis() {
	for (int i = 0; i < n; i++) vis[i] = false;
}
void reset() {
	for (int i = 0; i < n; i++) {
		adj[i].clear();
		grp[i].clear();
		for (int j = 0; j < n; j++) {
			conn[i][j] = -1;
		}
		dsupp[i] = i;
		nxt[i].clear();
		vis[i] = false;
	}
}
int DSUFind(int u) {
	if (dsupp[u] == u) return u;
	return (dsupp[u] = DSUFind(dsupp[u]));
}
void DSUMerge(int u, int v) {
	u = DSUFind(u); v = DSUFind(v);
	if (u != v) dsupp[v] = u;
}
vector<int> GetPath(int st) {
	resetvis();
	vector<int> res;
	while (true) {
		res.pb(st);
		vis[st] = true;
		bool found = false;
		for (int &v : nxt[st]) {
			if (!vis[v]) {
				st = v;
				found = true;
				break;
			}
		}
		if (!found) break;
	}
	return res;
}
vector<int> MakePath(vector<int> &v) {
	if (v.size() == 1) return {v[0]};
	if (v.size() == 2) {
		if (con(v[0], v[1])) return {v[0], v[1]};
		else return {v[0]};
	}
	if (v.size() == 3) {
		if (con(v[0], v[1]) && con(v[0], v[2])) return {v[1], v[0], v[2]};
		if (con(v[0], v[1]) && con(v[1], v[2])) return {v[0], v[1], v[2]};
		if (con(v[0], v[2]) && con(v[1], v[2])) return {v[0], v[2], v[1]};
		if (con(v[0], v[1])) return {v[0], v[1]};
		if (con(v[0], v[2])) return {v[0], v[2]};
		if (con(v[1], v[2])) return {v[1], v[2]};
		return {v[0]};
	}
	for (int i = 0; i < n; i++) {
		nxt[i].clear();
	}
	pair<pii, pii> cur = {{v[0], v[0]}, {v[1], v[1]}};
	for (int i = 2; i < (int)(v.size()); i++) {
		if (con(cur.ff.ff, cur.ss.ff)) {
			nxt[cur.ff.ff].pb(cur.ss.ff);
			nxt[cur.ss.ff].pb(cur.ff.ff);
			cur.ff.ff = cur.ss.ss;
			cur.ss = {v[i], v[i]};
		} else if (con(cur.ff.ff, v[i])) {
			nxt[cur.ff.ff].pb(v[i]);
			nxt[v[i]].pb(cur.ff.ff);
			cur.ff.ff = v[i];
		} else {
			conn[cur.ss.ff][v[i]] = conn[v[i]][cur.ss.ff] = 1;
			nxt[cur.ss.ff].pb(v[i]);
			nxt[v[i]].pb(cur.ss.ff);
			cur.ss.ff = v[i];
		}
	}
	int st;
	if (con(cur.ff.ff, cur.ss.ff)) {
		nxt[cur.ff.ff].pb(cur.ss.ff);
		nxt[cur.ss.ff].pb(cur.ff.ff);
		st = cur.ff.ss;
	} else if (con(cur.ff.ff, cur.ss.ss)) {
		nxt[cur.ff.ff].pb(cur.ss.ss);
		nxt[cur.ss.ss].pb(cur.ff.ff);
		st = cur.ff.ss;
	} else if (con(cur.ff.ss, cur.ss.ff)) {
		nxt[cur.ff.ss].pb(cur.ss.ff);
		nxt[cur.ss.ff].pb(cur.ff.ss);
		st = cur.ff.ff;
	} else if (con(cur.ff.ss, cur.ss.ss)) {
		nxt[cur.ff.ss].pb(cur.ss.ss);
		nxt[cur.ss.ss].pb(cur.ff.ss);
		st = cur.ff.ff;
	} else {
		vector<int> res[2];
		res[0] = GetPath(cur.ff.ff);
		res[1] = GetPath(cur.ss.ff);

		// cerr << "res0: ";
		// for (int &x : res[0]) cerr << x << ' ';
		// cerr << endl;
		// cerr << "res1: ";
		// for (int &x : res[1]) cerr << x << ' ';
		// cerr << endl;

		bool found = false;
		for (int i = 0; i < (int)(res[0].size()); i++) {
			for (int j = 0; j < (int)(res[1].size()); j++) {
				if (con(res[0][i], res[1][j])) {
					// cerr << "FOUND " << res[0][i] << ' ' << res[1][j] << endl;
					nxt[res[0][i]].pb(res[1][j]);
					nxt[res[1][j]].pb(res[0][i]);

					if (res[0].size() >= 3) {
						nxt[cur.ff.ff].pb(cur.ff.ss);
						nxt[cur.ff.ss].pb(cur.ff.ff);
						// cerr << "RES0 ";
						// for (int &x : res[0]) cerr << x << ' ';
						// cerr << endl;
						st = (i == 0 ? res[0].back() : res[0][i - 1]);
						// cerr << "ST " << st << endl;
						vector<int>::iterator it;
						for (it = nxt[st].begin(); it != nxt[st].end(); ++it) {
							if (*it == res[0][i]) {
								nxt[st].erase(it);
								break;
							}
						}
						for (it = nxt[res[0][i]].begin(); it != nxt[res[0][i]].end(); ++it) {
							if (*it == st) {
								nxt[res[0][i]].erase(it);
								break;
							}
						}
					} else {
						st = (res[0].size() == 2 ? res[0][i ^ 1] : res[0][i]);
					}

					if (res[1].size() >= 3) {
						nxt[cur.ss.ff].pb(cur.ss.ss);
						nxt[cur.ss.ss].pb(cur.ss.ff);
						int tar = (j == 0 ? res[1].back() : res[1][j + 1]);
						vector<int>::iterator it;
						for (it = nxt[tar].begin(); it != nxt[tar].end(); ++it) {
							if (*it == res[1][j]) {
								nxt[tar].erase(it);
								break;
							}
						}
						for (it = nxt[res[1][j]].begin(); it != nxt[res[1][j]].end(); ++it) {
							if (*it == tar) {
								nxt[res[1][j]].erase(it);
								break;
							}
						}
					}

					found = true;
					break;
				}
			}
			if (found) break;
		}
		if (!found) {
			while (true) continue;
		}
	}

	// cerr << "find path for: ";
	// for (int &x : v) cerr << x << ' ';
	// cerr << endl;
	
	vector<int> res = GetPath(st);

	// cerr << "st: " << st << endl;
	// cerr << "result: ";
	// for (int &x : res) cerr << x << ' ';
	// cerr << endl;

	return res;
}
vector<int> longest_trip(int N, int D)
{
	n = N;
	reset();
	if (D == 3) {
		vector<int> res(n);
		for (int i = 0; i < n; i++) res[i] = i;
		return res;
	}

	queue<int> q;
	for (int i = 0; i < n; i++) {
		grp[i] = {i};
		q.push(i);
	}
	while (q.size() >= 3) {
		int a = q.front(); q.pop();
		int b = q.front(); q.pop();
		int c = q.front(); q.pop();
		if (are_connected(grp[a], grp[b])) {
			DSUMerge(a, b);
			for (int &x : grp[b]) grp[a].pb(x);
			grp[b].clear();
			q.push(a);
			q.push(c);
		} else if (are_connected(grp[a], grp[c])) {
			DSUMerge(a, c);
			for (int &x : grp[c]) grp[a].pb(x);
			grp[c].clear();
			q.push(a);
			q.push(b);
		} else {
			DSUMerge(b, c);
			for (int &x : grp[c]) grp[b].pb(x);
			grp[c].clear();
			q.push(a);
			q.push(b);
		}
	}
	int fina = q.front(); q.pop();
	int finb = q.front(); q.pop();
	if (are_connected(grp[fina], grp[finb])) {
		DSUMerge(fina, finb);
		for (int &x : grp[finb]) grp[fina].pb(x);
		grp[finb].clear();
	}

	vector<int> best = {};
	for (int i = 0; i < n; i++) {
		if (grp[i].empty()) continue;
		vector<int> res = MakePath(grp[i]);
		if (res.size() > best.size()) {
			best = res;
		}
	}
	return best;
}
# Verdict Execution time Memory Grader output
1 Correct 0 ms 208 KB Output is correct
2 Correct 6 ms 588 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 4 ms 208 KB Output is correct
2 Correct 1 ms 208 KB Output is correct
3 Correct 1 ms 336 KB Output is correct
4 Correct 1 ms 336 KB Output is correct
5 Correct 1 ms 464 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 15 ms 208 KB Output is correct
2 Correct 12 ms 208 KB Output is correct
3 Correct 14 ms 336 KB Output is correct
4 Correct 17 ms 464 KB Output is correct
5 Correct 14 ms 592 KB Output is correct
6 Correct 19 ms 208 KB Output is correct
7 Correct 14 ms 208 KB Output is correct
8 Correct 12 ms 336 KB Output is correct
9 Correct 16 ms 336 KB Output is correct
10 Correct 14 ms 592 KB Output is correct
11 Correct 10 ms 592 KB Output is correct
12 Correct 15 ms 592 KB Output is correct
13 Correct 14 ms 592 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 11 ms 208 KB Output is correct
2 Correct 12 ms 208 KB Output is correct
3 Correct 13 ms 264 KB Output is correct
4 Correct 14 ms 464 KB Output is correct
5 Correct 16 ms 592 KB Output is correct
6 Correct 13 ms 208 KB Output is correct
7 Correct 13 ms 208 KB Output is correct
8 Correct 14 ms 384 KB Output is correct
9 Correct 11 ms 336 KB Output is correct
10 Correct 10 ms 728 KB Output is correct
11 Correct 18 ms 592 KB Output is correct
12 Correct 15 ms 612 KB Output is correct
13 Correct 14 ms 592 KB Output is correct
14 Correct 9 ms 208 KB Output is correct
15 Correct 11 ms 208 KB Output is correct
16 Correct 18 ms 356 KB Output is correct
17 Correct 12 ms 336 KB Output is correct
18 Correct 19 ms 336 KB Output is correct
19 Correct 18 ms 464 KB Output is correct
20 Correct 16 ms 336 KB Output is correct
21 Correct 18 ms 592 KB Output is correct
22 Correct 17 ms 592 KB Output is correct
23 Correct 20 ms 592 KB Output is correct
24 Correct 18 ms 592 KB Output is correct
25 Correct 12 ms 208 KB Output is correct
26 Correct 10 ms 208 KB Output is correct
27 Correct 14 ms 208 KB Output is correct
28 Correct 14 ms 208 KB Output is correct
29 Correct 13 ms 208 KB Output is correct
30 Correct 12 ms 336 KB Output is correct
31 Correct 18 ms 368 KB Output is correct
32 Correct 21 ms 396 KB Output is correct
33 Correct 14 ms 336 KB Output is correct
34 Correct 12 ms 440 KB Output is correct
35 Correct 21 ms 336 KB Output is correct
36 Correct 14 ms 592 KB Output is correct
37 Correct 16 ms 592 KB Output is correct
38 Correct 16 ms 596 KB Output is correct
39 Correct 24 ms 596 KB Output is correct
40 Correct 18 ms 592 KB Output is correct
41 Correct 22 ms 592 KB Output is correct
42 Correct 18 ms 592 KB Output is correct
43 Correct 16 ms 592 KB Output is correct
44 Correct 16 ms 592 KB Output is correct
45 Correct 12 ms 208 KB Output is correct
46 Correct 15 ms 208 KB Output is correct
47 Correct 14 ms 208 KB Output is correct
48 Correct 16 ms 336 KB Output is correct
49 Correct 12 ms 208 KB Output is correct
50 Correct 15 ms 336 KB Output is correct
51 Correct 46 ms 376 KB Output is correct
52 Correct 53 ms 384 KB Output is correct
53 Correct 16 ms 336 KB Output is correct
54 Correct 27 ms 336 KB Output is correct
55 Correct 29 ms 336 KB Output is correct
56 Correct 14 ms 636 KB Output is correct
57 Correct 39 ms 592 KB Output is correct
58 Correct 51 ms 612 KB Output is correct
59 Correct 140 ms 724 KB Output is correct
60 Correct 130 ms 608 KB Output is correct
61 Correct 87 ms 712 KB Output is correct
62 Correct 80 ms 612 KB Output is correct
63 Correct 107 ms 596 KB Output is correct
64 Correct 130 ms 596 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 11 ms 208 KB Output is correct
2 Correct 14 ms 208 KB Output is correct
3 Correct 12 ms 336 KB Output is correct
4 Correct 14 ms 464 KB Output is correct
5 Partially correct 16 ms 536 KB Output is partially correct
6 Correct 11 ms 208 KB Output is correct
7 Correct 14 ms 336 KB Output is correct
8 Correct 18 ms 504 KB Output is correct
9 Correct 14 ms 428 KB Output is correct
10 Partially correct 11 ms 592 KB Output is partially correct
11 Partially correct 16 ms 592 KB Output is partially correct
12 Partially correct 15 ms 592 KB Output is partially correct
13 Partially correct 19 ms 588 KB Output is partially correct
14 Correct 11 ms 208 KB Output is correct
15 Correct 11 ms 208 KB Output is correct
16 Correct 17 ms 336 KB Output is correct
17 Correct 15 ms 336 KB Output is correct
18 Correct 19 ms 336 KB Output is correct
19 Correct 17 ms 336 KB Output is correct
20 Correct 18 ms 336 KB Output is correct
21 Correct 15 ms 208 KB Output is correct
22 Correct 13 ms 256 KB Output is correct
23 Correct 18 ms 208 KB Output is correct
24 Correct 12 ms 208 KB Output is correct
25 Correct 15 ms 208 KB Output is correct
26 Correct 15 ms 336 KB Output is correct
27 Correct 18 ms 464 KB Output is correct
28 Correct 18 ms 336 KB Output is correct
29 Correct 10 ms 336 KB Output is correct
30 Correct 13 ms 336 KB Output is correct
31 Correct 17 ms 384 KB Output is correct
32 Correct 14 ms 260 KB Output is correct
33 Correct 15 ms 208 KB Output is correct
34 Correct 16 ms 336 KB Output is correct
35 Correct 14 ms 208 KB Output is correct
36 Correct 12 ms 208 KB Output is correct
37 Correct 16 ms 336 KB Output is correct
38 Partially correct 44 ms 392 KB Output is partially correct
39 Partially correct 48 ms 464 KB Output is partially correct
40 Correct 22 ms 336 KB Output is correct
41 Partially correct 27 ms 336 KB Output is partially correct
42 Partially correct 35 ms 336 KB Output is partially correct
43 Partially correct 16 ms 592 KB Output is partially correct
44 Partially correct 19 ms 592 KB Output is partially correct
45 Partially correct 10 ms 596 KB Output is partially correct
46 Partially correct 20 ms 592 KB Output is partially correct
47 Partially correct 17 ms 640 KB Output is partially correct
48 Partially correct 19 ms 592 KB Output is partially correct
49 Partially correct 18 ms 592 KB Output is partially correct
50 Partially correct 19 ms 636 KB Output is partially correct
51 Partially correct 20 ms 592 KB Output is partially correct
52 Partially correct 16 ms 592 KB Output is partially correct
53 Partially correct 22 ms 596 KB Output is partially correct
54 Partially correct 17 ms 604 KB Output is partially correct
55 Partially correct 19 ms 608 KB Output is partially correct
56 Partially correct 15 ms 592 KB Output is partially correct
57 Partially correct 24 ms 588 KB Output is partially correct
58 Partially correct 18 ms 596 KB Output is partially correct
59 Partially correct 24 ms 592 KB Output is partially correct
60 Partially correct 22 ms 596 KB Output is partially correct
61 Partially correct 23 ms 592 KB Output is partially correct
62 Partially correct 18 ms 592 KB Output is partially correct
63 Partially correct 45 ms 600 KB Output is partially correct
64 Partially correct 45 ms 600 KB Output is partially correct
65 Partially correct 143 ms 712 KB Output is partially correct
66 Partially correct 101 ms 604 KB Output is partially correct
67 Partially correct 94 ms 596 KB Output is partially correct
68 Partially correct 75 ms 600 KB Output is partially correct
69 Partially correct 120 ms 720 KB Output is partially correct
70 Partially correct 131 ms 600 KB Output is partially correct
71 Partially correct 46 ms 604 KB Output is partially correct
72 Partially correct 62 ms 600 KB Output is partially correct
73 Partially correct 232 ms 592 KB Output is partially correct
74 Partially correct 219 ms 592 KB Output is partially correct
75 Partially correct 286 ms 612 KB Output is partially correct
76 Partially correct 235 ms 600 KB Output is partially correct
77 Partially correct 48 ms 608 KB Output is partially correct
78 Partially correct 40 ms 604 KB Output is partially correct
79 Partially correct 216 ms 592 KB Output is partially correct
80 Partially correct 109 ms 592 KB Output is partially correct
81 Partially correct 138 ms 728 KB Output is partially correct
82 Partially correct 239 ms 612 KB Output is partially correct