Submission #557052

#	Time	Username	Problem	Language	Result	Execution time	Memory
557052		proma	Graph (BOI20_graph)	C++17	0 / 100	3 ms	2644 KiB

Graph

#include <bits/stdc++.h>

//#define int long long
#define endl "\n"
#define see(x) cout<<#x<<"="<<x<<"\n";

using namespace std;

const int N = 1e5+5;
const int INF = 1e9;

int n, m, flag, used[N], val[N], s[N];
vector <pair <int, int>> g[N];
vector <int> visited;
double x, res[N];

void dfs(int v, int p = 0) {
    used[v] = 1;
    visited.push_back(v);
    for (auto i: g[v]) {
        if (i.first == p) continue;
        if (used[i.first] and s[i.first] == s[v] and x == INF) {
            x = (i.second - val[i.first] - val[v]) / 2.0;
        }
        else if (!used[i.first]) {
            s[i.first] = -s[v];
            val[i.first] = i.second - val[v];
            dfs(i.first, v);
        }
    }
}

int32_t main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
/*
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
*/

    cin >> n >> m;

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

    for (int i = 1; i <= n; i ++) {
        if (!used[i]) {
            x = INF;
            s[i] = 1;
            val[i] = 0;
            visited.clear();
            dfs(i);
            if (x == INF) {
                vector <int> v;
                for (auto i: visited) {
                    v.push_back(val[i] * (-s[i]));
                }
                sort(v.begin(), v.end());
                int cnt = v.size();
                if (cnt % 2) x = v[cnt/2];
                else x = (v[cnt/2] + v[cnt/2+1]) / 2.0;
            }
            for (auto i: visited) {
                res[i] = s[i] * x + val[i];
            }
        }
    }

    for (int i = 1; i <= n; i ++) {
        for (auto j: g[i]) {
            if (res[i] + res[j.first] != j.second) {
                cout << "NO\n";
                return 0;
            }
        }
    }

    cout << "YES\n";
    for (int i = 1; i <= n; i ++) {
        cout << res[i] << " ";
    }

    return 0;
}

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