Submission #1049951

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
1049951	2024-08-09T06:19:09 Z	mychecksedad	Connecting Supertrees (IOI20_supertrees)	C++17	19 / 100	103 ms	26132 KB

supertrees

#include "supertrees.h"
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define pb push_back
#define vi vector<int>
 

struct Dsu{
	vector<int> p, s;
	Dsu(int n){
		p.resize(n+1);
		s.resize(n+1,1);
		for(int i = 1; i <= n; ++i ) p[i]=i;
	}
	int find(int v){
		if(p[v] == v)return v;
		return p[v]=find(p[v]);
	}
	void merge(int a, int b){
		a = find(a);
		b = find(b);
		if(a != b){
			if(s[a]>s[b]) swap(a,b);
			p[a] = b;
			s[b] += s[a];
		}
	}
};
vector<vector<int>> P;
bool solve(vector<int> v, vector<vector<int>> &ans){
	if(v.empty()) return 1;
	for(int u: v){
		for(int x: v){
			if(P[u][x] == 0 || P[u][x] == 3){
				return 0;
			}
		}
	}
	vector<int> cycle;
	vector<vector<int>> onepiece;
	vector<bool> used(v.size());
	for(int i = 0; i < v.size(); ++i){
		bool fulltwo = 1;
		for(int j = i + 1; j < v.size(); ++j){
			if(P[v[i]][v[j]] == 1){
				fulltwo = 0;
				onepiece.pb(vector<int>{v[i], v[j]});
				used[i] = used[j] = 1;
				for(int k = j + 1; k < v.size(); ++k){	
					if(!used[k]){
						int co = 0;
						for(int c: onepiece.back()){
							if(P[c][v[k]] == 1){
								++co;
							}
						}
						if(co != 0 && co != onepiece.back().size()){
							return 0;
						}
						if(co == onepiece.back().size()){
							onepiece.back().pb(v[k]);
							used[k] = 1;
						}
					}
				}
			}
		}
		if(fulltwo) cycle.pb(v[i]);
		// else assert(false);
	}


	for(auto x: onepiece){
		for(int j = 0; j + 1 < x.size(); ++j){
			ans[x[j]][x[j + 1]] = ans[x[j + 1]][x[j]] = 1;
		}
		cycle.pb(x[0]);
	}
	if(cycle.size() == 1 && v.size() == 1) return 1;
	if(cycle.size() == 2) return 0;
	for(int i = 0; i < cycle.size(); ++i){
		ans[cycle[i]][cycle[(i + 1) % cycle.size()]] = ans[cycle[(i + 1) % cycle.size()]][cycle[i]] = 1;
	}

	return 1;
}

int construct(std::vector<std::vector<int>> p) {
	int n = p.size();
	P = p;
	vector<vector<int>> answer(n, vector<int>(n));

	Dsu d(n);

	for(int i = 0; i < n; ++i){
		for(int j = 1; j < n; ++j){
			if(p[i][j] > 0) d.merge(i, j);
		}
	}

	vector<vector<int>> C(n);
	for(int i = 0; i < n; ++i){
		C[d.find(i)].pb(i);
	}
	for(auto v: C){
		bool ok = solve(v, answer);
		if(!ok) return 0;
	}


	build(answer);
	return 1;
}

Compilation message

supertrees.cpp: In function 'bool solve(std::vector<int>, std::vector<std::vector<int> >&)':
supertrees.cpp:43:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |  for(int i = 0; i < v.size(); ++i){
      |                 ~~^~~~~~~~~~
supertrees.cpp:45:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |   for(int j = i + 1; j < v.size(); ++j){
      |                      ~~^~~~~~~~~~
supertrees.cpp:50:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |     for(int k = j + 1; k < v.size(); ++k){
      |                        ~~^~~~~~~~~~
supertrees.cpp:58:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |       if(co != 0 && co != onepiece.back().size()){
      |                     ~~~^~~~~~~~~~~~~~~~~~~~~~~~~
supertrees.cpp:61:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   61 |       if(co == onepiece.back().size()){
      |          ~~~^~~~~~~~~~~~~~~~~~~~~~~~~
supertrees.cpp:75:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   75 |   for(int j = 0; j + 1 < x.size(); ++j){
      |                  ~~~~~~^~~~~~~~~~
supertrees.cpp:82:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   82 |  for(int i = 0; i < cycle.size(); ++i){
      |                 ~~^~~~~~~~~~~~~~

Subtask #1
0 / 11.0

#	Verdict	Memory	Grader output
1	Correct	348 KB	Output is correct
2	Incorrect	348 KB	Answer gives possible 0 while actual possible 1
3	Halted	0 KB	-

Subtask #2
0 / 10.0

#	Verdict	Memory	Grader output
1	Correct	348 KB	Output is correct
2	Incorrect	348 KB	Answer gives possible 0 while actual possible 1
3	Halted	0 KB	-

Subtask #3
19.0 / 19.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	348 KB	Output is correct
2	Correct	0 ms	348 KB	Output is correct
3	Correct	0 ms	348 KB	Output is correct
4	Correct	0 ms	348 KB	Output is correct
5	Correct	0 ms	348 KB	Output is correct
6	Correct	0 ms	348 KB	Output is correct
7	Correct	0 ms	348 KB	Output is correct
8	Correct	4 ms	1372 KB	Output is correct
9	Correct	99 ms	26132 KB	Output is correct
10	Correct	0 ms	348 KB	Output is correct
11	Correct	0 ms	348 KB	Output is correct
12	Correct	6 ms	1372 KB	Output is correct
13	Correct	101 ms	26128 KB	Output is correct
14	Correct	1 ms	348 KB	Output is correct
15	Correct	0 ms	348 KB	Output is correct
16	Correct	2 ms	860 KB	Output is correct
17	Correct	57 ms	16140 KB	Output is correct
18	Correct	0 ms	344 KB	Output is correct
19	Correct	0 ms	348 KB	Output is correct
20	Correct	0 ms	348 KB	Output is correct
21	Correct	24 ms	6888 KB	Output is correct
22	Correct	103 ms	26116 KB	Output is correct
23	Correct	96 ms	25936 KB	Output is correct
24	Correct	100 ms	25992 KB	Output is correct
25	Correct	41 ms	16208 KB	Output is correct
26	Correct	43 ms	16052 KB	Output is correct
27	Correct	96 ms	26132 KB	Output is correct
28	Correct	100 ms	25956 KB	Output is correct
29	Correct	50 ms	16136 KB	Output is correct