Submission #550727

#	Time	Username	Problem	Language	Result	Execution time	Memory
550727		Zhora_004	Graph (BOI20_graph)	C++17	5 / 100	1 ms	212 KiB

Graph

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <cmath>
#include <algorithm>
#include <vector>
#include <set>
#include <unordered_set>
#include <queue>
#include <deque>
#include <string>
#include <sstream>
#include <iomanip>
#include <map>
#include <unordered_map>
#include <stack>
#include <cstdio>
#include <climits>
#include <tuple>
#include <ctime>
#include <cstring>
#include <numeric>
#include <functional>
#include <chrono>
#include <cassert>
#include <bitset>
#include <fstream>
//#include <bit>
//#include <ranges>
//#include <numbers>
#define itn int
#define sacnf scanf
#define sz(a) ((int)((a).size()))
// printf("%.10f\n", ans);
/*ofstream fout("timeline.out");
ifstream fin("timeline.in");*/
using ll = long long;
using namespace std;
const ll mod = 1e9 + 7;
const int N = 2e5 + 1, inf = 1e9;
int n, m, a, b;
vector<bool> used;
vector<int> ans, comp;
vector<vector<pair<int, int>>> gp;

void dfs1(int u)
{
    used[u] = 1;
    comp.push_back(u);
    for (pair<int, int>& p : gp[u])
    {
        if (p.second == 4) a = u, b = p.first;
        if (!used[p.first]) dfs1(p.first);
    }
}

void dfs2(int u, int val, int& sum)
{
    // -4 <= val <= 4
    // else optimize 
    used[u] = 1;
    ans[u] = val;
    sum += abs(val);
    for (pair<int, int>& p : gp[u]) if (!used[p.first]) dfs2(p.first, p.second - val, sum);
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n >> m;
    used = vector<bool>(n);
    ans = vector<int>(n, inf);
    gp = vector<vector<pair<int, int>>>(n);
    for (int i = 0; i < m; i++)
    {
        int u, v, w;
        cin >> u >> v >> w;
        gp[--u].push_back({ --v, w * 2 });
        gp[v].push_back({ u, w * 2 });
    }
    for (int i = 0; i < n; i++)
    {
        if (!used[i])
        {
            comp.clear();
            a = b = -1;
            dfs1(i);
            int mn = inf, num = -1;
            int val = -100;
            if (a == -1) a = i;
            for (; val <= 100; val++)
            {
                for (int& u : comp) used[u] = 0;
                int sum = 0;
                dfs2(a, val, sum);
                for (int& u : comp)
                {
                    for (pair<int, int>& p : gp[u])
                    {
                        int v = p.first;
                        if (!(-4 <= ans[u] && ans[u] <= 4 && -4 <= ans[v] && ans[v] <= 4 && ans[u] + ans[v] == p.second))
                        {
                            sum = inf;
                            break;
                        }
                    }
                    if (sum == inf) break;
                }
                if (sum < mn) mn = sum, num = val;
            }
            if (num != -1)
            {
                for (int& u : comp) used[u] = 0;
                int sum = 0;
                dfs2(a, num, sum);
            }
            else return cout << "NO", 0;
        }
    }
    cout << "YES\n";
    for (int i = 0; i < n; i++)
    {
        if (ans[i] == -1) cout << "-0.5 ";
        else
        {
            cout << ans[i] / 2;
            if (abs(ans[i]) & 1) cout << ".5";
            cout << " ";
        }
    }

    return 0;
}

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