Submission #977800

#	Time	Username	Problem	Language	Result	Execution time	Memory
977800		SmuggingSpun	Connecting Supertrees (IOI20_supertrees)	C++14	21 / 100	183 ms	22052 KiB

supertrees

#include "supertrees.h"
#include<bits/stdc++.h>
using namespace std;
int construct(vector<vector<int>>p){
	int n = p.size();
	bool is_sub1 = true, is_sub2 = true, is_sub3 = true;
	for(int i = 0; i < n; i++){
		for(int j = 0; j < n; j++){
			if(p[i][j] != 1){
				is_sub1 = false;
			}
			if(p[i][j] > 1){
				is_sub2 = false;
			}
			if(p[i][j] != 0 && p[i][j] != 2){
				is_sub3 = false;
			}
		}
	}
	if(is_sub1){
		p = vector<vector<int>>(n, vector<int>(n, 0));
		for(int i = 1; i < n; i++){
			p[i][i - 1] = p[i - 1][i] = 1;
		}
		build(p);
		return 1;
	}
	if(is_sub2){
		vector<int>par(n);
		iota(par.begin(), par.end(), 0);
		function<int(int)>find_set;
		find_set = [&] (int n){
			return n == par[n] ? n : par[n] = find_set(par[n]);	
		};
		function<void(int, int)>merge = [&] (int a, int b){
			par[find_set(a)] = find_set(b);
		};
		vector<bool>vis(n, false);
		vector<vector<int>>edge(n);
		for(int i = 0; i < n; i++){
			if(vis[i]){
				for(int j = 0; j < n; j++){
					if(i != j && int(find_set(i) == find_set(j)) != p[i][j]){
						return 0;
					}
				}
				continue;
			}
			for(int j = 0; j < n; j++){
				if(i != j && p[i][j] == 0 && find_set(i) == find_set(j)){
					return 0;
				}
				if(p[i][j] == 1){
					merge(i, j);
					vis[j] = true;
				}
			}
		}
		for(int i = 0; i < n; i++){
			edge[find_set(i)].emplace_back(i);
		}
		p = vector<vector<int>>(n, vector<int>(n, 0));
		for(int i = 0; i < n; i++){
			for(int j = 1; j < edge[i].size(); j++){
				p[edge[i][j]][edge[i][j - 1]] = p[edge[i][j - 1]][edge[i][j]] = 1;
			}
		}
		build(p);
		return 1;
	}
	if(is_sub3){
		vector<int>par(n);
		iota(par.begin(), par.end(), 0);
		function<int(int)>find_set;
		find_set = [&] (int n){
			return n == par[n] ? n : par[n] = find_set(par[n]);	
		};
		function<void(int, int)>merge = [&] (int a, int b){
			par[find_set(a)] = find_set(b);
		};
		vector<bool>vis(n, false);
		vector<vector<int>>edge(n);
		for(int i = 0; i < n; i++){
			if(vis[i]){
				for(int j = 0; j < n; j++){
					if(i != j && (find_set(i) == find_set(j)) != (p[i][j] == 2)){
						return 0;
					}
				}
				continue;
			}
			for(int j = 0; j < n; j++){
				if(i != j && p[i][j] == 0 && find_set(i) == find_set(j)){
					return 0;
				}
				if(p[i][j] == 2){
					merge(i, j);
					vis[j] = true;
				}
			}
		}
		for(int i = 0; i < n; i++){
			edge[find_set(i)].emplace_back(i);
		}
		p = vector<vector<int>>(n, vector<int>(n, 0));
		for(int i = 0; i < n; i++){
			if(edge[i].size() == 2){
				return 0;
			}
			if(edge[i].size() > 2){
				edge[i].emplace_back(edge[i][0]);
				for(int j = 1; j < edge[i].size(); j++){
					p[edge[i][j]][edge[i][j - 1]] = p[edge[i][j - 1]][edge[i][j]] = 1;
				}
			}
		}
		build(p);
		return 1;
	}
	vector<bool>vis(n, false);
	vector<vector<int>>ans(n, vector<int>(n, 0));
	for(int i = 0; i < n; i++){
		if(!vis[i]){
			vector<int>vertex;
			for(int j = i; j < n; j++){
				if(p[i][j] > 0){
					vertex.emplace_back(j);
					vis[j] = true;
				}
			}
			vector<vector<int>>part;
			for(int& u : vertex){
				for(int& v : vertex){
					if(p[u][v] == 0){
						return 0;
					}
				}
				if(vis[u]){
					part.emplace_back(vector<int>());
					for(int& v : vertex){
						if(vis[v] && p[u][v] == 1){
							part.back().emplace_back(v);
							vis[v] = false;
						}
					}
				}
			}
			if(part.size() == 2){
				return 0;
			}
			for(auto& x : part){
				for(auto& y : part){
					for(int& i : x){
						for(int& j : y){
							if((x[0] != y[0]) != (p[i][j] == 2)){
								return 0;
							}
						}
					}
				}
				for(int i = 1; i < x.size(); i++){
					ans[x[i]][x[i - 1]] = ans[x[i - 1]][x[i]] = 1;
				}
			}
			for(int i = 0; i < part.size(); i++){
				int u = part[i][0], v = part[(i + 1) % part.size()][0];
				ans[u][v] = ans[v][u] = 1;
			}
			for(int& i : vertex){
				for(int j = 0; j < n; j++){
					if(vis[j] && p[i][j] > 0){
						return 0;
					}
				}
			}
			for(int& i : vertex){
				vis[i] = true;
			}
		}
	}
	build(ans);
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:64:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   64 |    for(int j = 1; j < edge[i].size(); j++){
      |                   ~~^~~~~~~~~~~~~~~~
supertrees.cpp:112:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  112 |     for(int j = 1; j < edge[i].size(); j++){
      |                    ~~^~~~~~~~~~~~~~~~
supertrees.cpp:161:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  161 |     for(int i = 1; i < x.size(); i++){
      |                    ~~^~~~~~~~~~
supertrees.cpp:165:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  165 |    for(int i = 0; i < part.size(); i++){
      |                   ~~^~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 10 / 10
• Subtask 3: 0 / 19
• Subtask 4: 0 / 35
• Subtask 5: 0 / 21
• Subtask 6: 0 / 4