Submission #859450

#	Time	Username	Problem	Language	Result	Execution time	Memory
859450		maks007	Graph (BOI20_graph)	C++14	0 / 100	0 ms	348 KiB

Graph

#include "bits/stdc++.h"
 
using namespace std;
 
#define int long long
 
vector <vector <pair <int,int>>> g;
vector <int> used;
vector <int> comp;

#define int long long

void dfs(int v) {
	used[v] = 1;
	for(auto [i, j] : g[v]) {
		if(used[i] == LLONG_MAX) dfs(i);
	}
}

void get_comps() {
	for(int i = 0; i < used.size(); i ++) {
		if(used[i] == LLONG_MAX) {
			dfs(i);
			comp.push_back(i);
		}
	}
}

int check(int v) {
	int f = 1;
	for(auto [i, j] : g[v]) {
		if(used[i] == LLONG_MAX) {
			used[i] = j - used[v];
			f = min(f, check(i));
		}else {
			if(used[i] + used[v] != j) f = 0;
		}
	}
	return f;
}

vector <pair <int,int>> rec(int v) {
	int mn = LLONG_MAX;
	vector <pair <int,int>> ans;
	for(int val = -200; val <= 200; val += 25) {
		for(auto &j : used) j = LLONG_MAX;
		used[v] = val;
		if(check(v)) {
			int cnt = 0;
			for(auto &j : used) {
				if(j == LLONG_MAX) continue;
				cnt += abs(j);
			}
			if(cnt <= mn) {
				mn = cnt;
				for(int j = 0; j < used.size(); j ++) {
					if(used[j] == LLONG_MAX) continue;
					ans.push_back({j, used[j]});
				}
			}
		}
		// cout << val << " ";
		// if(val == 0.5) {
		// 	for(auto j : used) cout << j << " ";
		// }
	}
	if(mn == LLONG_MAX) {
		cout << "NO\n";
		exit(0);
	}
	return ans;
}

signed main () {
	ios::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	int n, m;
	cin >> n >> m;
	g.resize(n);
	used.resize(n, LLONG_MAX);

	for(int i = 0; i < m; i ++) {
		int u, v;
		cin >> u >> v;
		u --, v --;
		int w;
		cin >> w;
		g[u].push_back({v, w*10});
		g[v].push_back({u, w*10});
	}

	get_comps();
	// assert(comp.size() < 2);
	for(auto &j : used) j = LLONG_MAX;
	vector <vector <pair <int,int>>> res;
	for(auto i : comp) {
		res.push_back(rec(i));
	}
	cout << "YES\n";
	vector <int> ans(n);
	for(auto i : res) {
		for(auto j : i) ans[j.first] = j.second;
	}
	for(auto i : ans) cout << fixed << setprecision(6) << (double)i*0.1 << " ";
	return 0;
}

Compilation message (stderr)

Graph.cpp: In function 'void dfs(long long int)':
Graph.cpp:15:11: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   15 |  for(auto [i, j] : g[v]) {
      |           ^
Graph.cpp: In function 'void get_comps()':
Graph.cpp:21:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |  for(int i = 0; i < used.size(); i ++) {
      |                 ~~^~~~~~~~~~~~~
Graph.cpp: In function 'long long int check(long long int)':
Graph.cpp:31:11: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   31 |  for(auto [i, j] : g[v]) {
      |           ^
Graph.cpp: In function 'std::vector<std::pair<long long int, long long int> > rec(long long int)':
Graph.cpp:56:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |     for(int j = 0; j < used.size(); j ++) {
      |                    ~~^~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 12
• Subtask 3: 0 / 17
• Subtask 4: 0 / 24
• Subtask 5: 0 / 42