oj.uz

Submission #840748

# Submission time Handle Problem Language Result Execution time Memory
840748 2023-08-31T16:40:15 Z happypotato Longest Trip (IOI23_longesttrip) C++17
85 / 100
 20 ms 716 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];
int callcnt;
bool con(int x, int y) {
	// cerr << "CALLx " << x << ' ' << y << endl;
	if (x == y) return (conn[x][x] = 1);
	if (conn[x][y] != -1) return conn[x][y];
	callcnt++;
	return (conn[x][y] = conn[y][x] = are_connected({x}, {y}));
}
bool Con(vector<int> x, vector<int> y) {
	if (x.size() == 1 && y.size() == 1) {
		return con(x[0], y[0]);
	}
	// cerr << "CALL\n";
	// for (int &cur : x) cerr << cur << ' ';
	// cerr << endl;
	// for (int &cur : y) cerr << cur << ' ';
	// cerr << endl;
	callcnt++;
	return 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() {
	callcnt = 0;
	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];
		}
	}
	vector<int> res[2];
	res[0] = GetPath(cur.ff.ff);
	res[1] = GetPath(cur.ss.ff);
	if (!Con(res[0], res[1])) {
		return (res[0].size() >= res[1].size() ? res[0] : res[1]);
	}
	int st;
	vector<int> temp[2];
	temp[0].pb(cur.ff.ff); if (cur.ff.ff != cur.ff.ss) temp[0].pb(cur.ff.ss);
	temp[1].pb(cur.ss.ff); if (cur.ss.ff != cur.ss.ss) temp[1].pb(cur.ss.ss);
	if (Con(temp[0], temp[1])) {
		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> take[2];
		take[0] = res[0];
		take[1] = res[1];

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

		vector<int> split[2];
		while (take[0].size() >= 2) {
			split[0].clear();
			split[1].clear();
			int cut = (int)(take[0].size()) / 2;
			for (int i = 0; i < cut; i++) split[0].pb(take[0][i]);
			for (int i = cut; i < (int)(take[0].size()); i++) split[1].pb(take[0][i]);
			if (Con(split[0], take[1])) take[0] = split[0];
			else take[0] = split[1];
		}
		while (take[1].size() >= 2) {
			split[0].clear();
			split[1].clear();
			int cut = (int)(take[1].size()) / 2;
			for (int i = 0; i < cut; i++) split[0].pb(take[1][i]);
			for (int i = cut; i < (int)(take[1].size()); i++) split[1].pb(take[1][i]);
			if (Con(take[0], split[0])) take[1] = split[0];
			else take[1] = split[1];
		}

		bool found = false;
		for (int i = 0; i < (int)(res[0].size()); i++) {
			if (res[0][i] != take[0][0]) continue;
			for (int j = 0; j < (int)(res[1].size()); j++) {
				if (res[1][j] != take[1][0]) continue;
				if (true) {
					// 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;
		}

		// cerr << "END\n";
	}

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

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

	return fin;
}
vector<int> longest_trip(int N, int D)
{
	n = N;
	reset();

	// queue<int> q;
	// for (int i = 0; i < n; i++) {
	// 	grp[i].clear();
	// 	grp[i].pb(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();
	// 	// cerr << a << ' ' << b << ' ' << c << endl;
	// 	if (Con(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 (Con(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 (Con(grp[fina], grp[finb])) {
	// 	DSUMerge(fina, finb);
	// 	for (int &x : grp[finb]) grp[fina].pb(x);
	// 	grp[finb].clear();
	// }

	// // cerr << "CALLCNT " << callcnt << endl;

	// 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;

	vector<int> res(n);
	for (int i = 0; i < n; i++) res[i] = i;
	return MakePath(res);
}

Compilation message

longesttrip.cpp: In function 'std::vector<int> MakePath(std::vector<int>&)':
longesttrip.cpp:246:30: warning: 'st' may be used uninitialized in this function [-Wmaybe-uninitialized]
  246 |  vector<int> fin = GetPath(st);
      |                              ^

Subtask #0
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 208 KB Output is correct
2 Correct 3 ms 464 KB Output is correct

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 208 KB Output is correct
2 Correct 11 ms 336 KB Output is correct
3 Correct 5 ms 336 KB Output is correct
4 Correct 8 ms 336 KB Output is correct
5 Correct 10 ms 464 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 208 KB Output is correct
2 Correct 12 ms 356 KB Output is correct
3 Correct 5 ms 336 KB Output is correct
4 Correct 10 ms 336 KB Output is correct
5 Correct 10 ms 464 KB Output is correct
6 Correct 6 ms 208 KB Output is correct
7 Correct 12 ms 208 KB Output is correct
8 Correct 10 ms 336 KB Output is correct
9 Correct 10 ms 336 KB Output is correct
10 Correct 10 ms 464 KB Output is correct
11 Correct 7 ms 464 KB Output is correct
12 Correct 10 ms 464 KB Output is correct
13 Correct 9 ms 464 KB Output is correct

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 208 KB Output is correct
2 Correct 9 ms 208 KB Output is correct
3 Correct 10 ms 336 KB Output is correct
4 Correct 8 ms 356 KB Output is correct
5 Correct 10 ms 464 KB Output is correct
6 Correct 11 ms 208 KB Output is correct
7 Correct 9 ms 336 KB Output is correct
8 Correct 6 ms 336 KB Output is correct
9 Correct 7 ms 336 KB Output is correct
10 Correct 9 ms 464 KB Output is correct
11 Correct 10 ms 464 KB Output is correct
12 Correct 11 ms 464 KB Output is correct
13 Correct 10 ms 640 KB Output is correct
14 Correct 12 ms 208 KB Output is correct
15 Correct 13 ms 208 KB Output is correct
16 Correct 13 ms 336 KB Output is correct
17 Correct 7 ms 336 KB Output is correct
18 Correct 12 ms 336 KB Output is correct
19 Correct 5 ms 336 KB Output is correct
20 Correct 11 ms 336 KB Output is correct
21 Correct 10 ms 464 KB Output is correct
22 Correct 7 ms 592 KB Output is correct
23 Correct 5 ms 464 KB Output is correct
24 Correct 8 ms 464 KB Output is correct
25 Correct 9 ms 208 KB Output is correct
26 Correct 13 ms 208 KB Output is correct
27 Correct 12 ms 208 KB Output is correct
28 Correct 15 ms 208 KB Output is correct
29 Correct 8 ms 336 KB Output is correct
30 Correct 11 ms 336 KB Output is correct
31 Correct 15 ms 336 KB Output is correct
32 Correct 10 ms 384 KB Output is correct
33 Correct 16 ms 336 KB Output is correct
34 Correct 15 ms 424 KB Output is correct
35 Correct 14 ms 336 KB Output is correct
36 Correct 11 ms 464 KB Output is correct
37 Correct 17 ms 580 KB Output is correct
38 Correct 12 ms 644 KB Output is correct
39 Correct 15 ms 464 KB Output is correct
40 Correct 11 ms 592 KB Output is correct
41 Correct 14 ms 464 KB Output is correct
42 Correct 14 ms 464 KB Output is correct
43 Correct 14 ms 592 KB Output is correct
44 Correct 11 ms 592 KB Output is correct
45 Correct 15 ms 208 KB Output is correct
46 Correct 14 ms 208 KB Output is correct
47 Correct 15 ms 208 KB Output is correct
48 Correct 11 ms 208 KB Output is correct
49 Correct 11 ms 208 KB Output is correct
50 Correct 12 ms 336 KB Output is correct
51 Correct 18 ms 336 KB Output is correct
52 Correct 10 ms 336 KB Output is correct
53 Correct 10 ms 336 KB Output is correct
54 Correct 18 ms 336 KB Output is correct
55 Correct 11 ms 336 KB Output is correct
56 Correct 5 ms 604 KB Output is correct
57 Correct 15 ms 592 KB Output is correct
58 Correct 13 ms 592 KB Output is correct
59 Correct 10 ms 592 KB Output is correct
60 Correct 13 ms 716 KB Output is correct
61 Correct 12 ms 596 KB Output is correct
62 Correct 13 ms 464 KB Output is correct
63 Correct 15 ms 572 KB Output is correct
64 Correct 11 ms 592 KB Output is correct

Subtask #4
45.0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 208 KB Output is correct
2 Correct 9 ms 208 KB Output is correct
3 Correct 9 ms 336 KB Output is correct
4 Correct 9 ms 336 KB Output is correct
5 Correct 7 ms 464 KB Output is correct
6 Correct 7 ms 208 KB Output is correct
7 Correct 10 ms 208 KB Output is correct
8 Correct 9 ms 336 KB Output is correct
9 Correct 10 ms 336 KB Output is correct
10 Correct 7 ms 464 KB Output is correct
11 Correct 9 ms 464 KB Output is correct
12 Correct 9 ms 464 KB Output is correct
13 Correct 9 ms 464 KB Output is correct
14 Correct 10 ms 208 KB Output is correct
15 Correct 12 ms 208 KB Output is correct
16 Correct 13 ms 336 KB Output is correct
17 Correct 13 ms 336 KB Output is correct
18 Correct 11 ms 336 KB Output is correct
19 Correct 8 ms 336 KB Output is correct
20 Correct 11 ms 336 KB Output is correct
21 Correct 11 ms 208 KB Output is correct
22 Correct 10 ms 208 KB Output is correct
23 Correct 7 ms 208 KB Output is correct
24 Correct 13 ms 208 KB Output is correct
25 Correct 10 ms 208 KB Output is correct
26 Correct 14 ms 336 KB Output is correct
27 Correct 15 ms 336 KB Output is correct
28 Correct 10 ms 336 KB Output is correct
29 Correct 18 ms 388 KB Output is correct
30 Correct 9 ms 336 KB Output is correct
31 Correct 15 ms 336 KB Output is correct
32 Correct 16 ms 208 KB Output is correct
33 Correct 16 ms 208 KB Output is correct
34 Correct 11 ms 208 KB Output is correct
35 Correct 14 ms 208 KB Output is correct
36 Correct 14 ms 208 KB Output is correct
37 Correct 12 ms 336 KB Output is correct
38 Correct 8 ms 336 KB Output is correct
39 Correct 13 ms 336 KB Output is correct
40 Correct 12 ms 336 KB Output is correct
41 Correct 14 ms 336 KB Output is correct
42 Correct 16 ms 336 KB Output is correct
43 Correct 7 ms 464 KB Output is correct
44 Correct 6 ms 464 KB Output is correct
45 Correct 11 ms 592 KB Output is correct
46 Correct 10 ms 464 KB Output is correct
47 Partially correct 10 ms 464 KB Output is partially correct
48 Partially correct 20 ms 464 KB Output is partially correct
49 Partially correct 15 ms 592 KB Output is partially correct
50 Partially correct 11 ms 592 KB Output is partially correct
51 Partially correct 13 ms 464 KB Output is partially correct
52 Correct 13 ms 464 KB Output is correct
53 Correct 9 ms 464 KB Output is correct
54 Correct 10 ms 464 KB Output is correct
55 Correct 14 ms 464 KB Output is correct
56 Partially correct 9 ms 592 KB Output is partially correct
57 Partially correct 15 ms 592 KB Output is partially correct
58 Partially correct 13 ms 592 KB Output is partially correct
59 Partially correct 14 ms 464 KB Output is partially correct
60 Correct 14 ms 592 KB Output is correct
61 Correct 12 ms 464 KB Output is correct
62 Correct 8 ms 592 KB Output is correct
63 Partially correct 12 ms 592 KB Output is partially correct
64 Partially correct 11 ms 592 KB Output is partially correct
65 Partially correct 12 ms 464 KB Output is partially correct
66 Partially correct 11 ms 588 KB Output is partially correct
67 Correct 12 ms 592 KB Output is correct
68 Correct 13 ms 592 KB Output is correct
69 Correct 15 ms 592 KB Output is correct
70 Correct 8 ms 592 KB Output is correct
71 Partially correct 16 ms 592 KB Output is partially correct
72 Partially correct 17 ms 592 KB Output is partially correct
73 Partially correct 15 ms 592 KB Output is partially correct
74 Partially correct 11 ms 592 KB Output is partially correct
75 Correct 15 ms 592 KB Output is correct
76 Correct 15 ms 576 KB Output is correct
77 Partially correct 16 ms 592 KB Output is partially correct
78 Partially correct 16 ms 592 KB Output is partially correct
79 Partially correct 10 ms 592 KB Output is partially correct
80 Partially correct 14 ms 592 KB Output is partially correct
81 Correct 7 ms 592 KB Output is correct
82 Correct 13 ms 580 KB Output is correct