oj.uz

Submission #839895

# Submission time Handle Problem Language Result Execution time Memory
839895 2023-08-30T20:10:53 Z happypotato Longest Trip (IOI23_longesttrip) C++17
15 / 100
 1000 ms 764 KB 
#include "longesttrip.h"
 
#include <bits/stdc++.h>
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];
bool con[mxN][mxN];
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++) {
			con[i][j] = 0;
		}
		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 if (con[cur.ss.ff][v[i]]) {
			nxt[cur.ss.ff].pb(v[i]);
			nxt[v[i]].pb(cur.ss.ff);
			cur.ss.ff = v[i];
		} else {
			while (true) continue;
		}
	}
	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;
	}
	for (int i = 0; i < n; i++) {
		for (int j = i + 1; j < n; j++) {
			if (are_connected({i}, {j})) {
				adj[i].pb(j);
				adj[j].pb(i);
				con[i][j] = con[j][i] = true;
				DSUMerge(i, j);
			}
		}
	}
	for (int i = 0; i < n; i++) {
		grp[DSUFind(i)].pb(i);
	}
	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;
}
// after contest 60 submission

Subtask #0
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 208 KB Output is correct
2 Correct 217 ms 584 KB Output is correct

Subtask #1
5.0 / 5.0

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

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 208 KB Output is correct
2 Correct 41 ms 208 KB Output is correct
3 Correct 185 ms 336 KB Output is correct
4 Correct 331 ms 380 KB Output is correct
5 Correct 691 ms 648 KB Output is correct
6 Correct 9 ms 208 KB Output is correct
7 Correct 36 ms 208 KB Output is correct
8 Correct 203 ms 336 KB Output is correct
9 Correct 434 ms 336 KB Output is correct
10 Correct 864 ms 580 KB Output is correct
11 Correct 916 ms 704 KB Output is correct
12 Correct 819 ms 552 KB Output is correct
13 Correct 743 ms 656 KB Output is correct

Subtask #3
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 208 KB Output is correct
2 Correct 28 ms 208 KB Output is correct
3 Correct 130 ms 336 KB Output is correct
4 Correct 332 ms 392 KB Output is correct
5 Correct 776 ms 604 KB Output is correct
6 Correct 9 ms 208 KB Output is correct
7 Correct 27 ms 208 KB Output is correct
8 Correct 195 ms 336 KB Output is correct
9 Correct 305 ms 380 KB Output is correct
10 Correct 952 ms 628 KB Output is correct
11 Correct 946 ms 708 KB Output is correct
12 Correct 775 ms 656 KB Output is correct
13 Correct 916 ms 640 KB Output is correct
14 Correct 12 ms 208 KB Output is correct
15 Correct 19 ms 208 KB Output is correct
16 Correct 50 ms 324 KB Output is correct
17 Correct 81 ms 208 KB Output is correct
18 Correct 143 ms 344 KB Output is correct
19 Correct 351 ms 352 KB Output is correct
20 Correct 391 ms 392 KB Output is correct
21 Correct 853 ms 668 KB Output is correct
22 Correct 906 ms 684 KB Output is correct
23 Correct 986 ms 584 KB Output is correct
24 Correct 839 ms 712 KB Output is correct
25 Correct 17 ms 208 KB Output is correct
26 Correct 16 ms 208 KB Output is correct
27 Correct 40 ms 208 KB Output is correct
28 Correct 42 ms 208 KB Output is correct
29 Correct 23 ms 208 KB Output is correct
30 Correct 199 ms 488 KB Output is correct
31 Correct 228 ms 340 KB Output is correct
32 Correct 233 ms 340 KB Output is correct
33 Correct 307 ms 468 KB Output is correct
34 Correct 325 ms 396 KB Output is correct
35 Correct 281 ms 380 KB Output is correct
36 Correct 940 ms 648 KB Output is correct
37 Correct 976 ms 764 KB Output is correct
38 Execution timed out 1105 ms 652 KB Time limit exceeded
39 Halted 0 ms 0 KB -

Subtask #4
0.0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 208 KB Output is correct
2 Correct 38 ms 208 KB Output is correct
3 Partially correct 157 ms 360 KB Output is partially correct
4 Partially correct 306 ms 392 KB Output is partially correct
5 Execution timed out 1020 ms 648 KB Time limit exceeded
6 Halted 0 ms 0 KB -