Submission #1129955

#	Time	Username	Problem	Language	Result	Execution time	Memory
1129955		vladilius	Graph (BOI20_graph)	C++20	0 / 100	1 ms	328 KiB

Graph

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define pb push_back
#define ff first
#define ss second
#define arr3 array<int, 3>

struct dsu{
    vector<int> sz, p;
    int n;
    dsu(int ns){
        n = ns;
        sz.resize(n + 1);
        p.resize(n + 1);
        for (int i = 1; i <= n; i++){
            p[i] = i;
            sz[i] = 1;
        }
    }
    int get(int v){
        if (p[v] != v){
            p[v] = get(p[v]);
        }
        return p[v];
    }
    bool unite(int x, int y){
        x = get(x); y = get(y);
        if (x == y) return 0;
        if (sz[x] > sz[y]) swap(x, y);
        p[x] = y;
        sz[y] += sz[x];
        return 1;
    }
};

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    
    int n, m; cin>>n>>m;
    vector<arr3> ed;
    while (m--){
        int x, y, w; cin>>x>>y>>w;
        ed.pb({x, y, w});
    }
    vector<pii> g[n + 1];
    dsu T(n);
    for (auto [x, y, w]: ed){
        if (T.unite(x, y)){
            g[x].pb({y, w});
            g[y].pb({x, w});
        }
    }
    
    for (int i = 2; i <= n; i++){
        if (T.get(i) != T.get(1)){
            cout<<"NO"<<"\n";
            return 0;
        }
    }
    
    vector<int> a(n + 1), b(n + 1);
    function<void(int, int)> dfs = [&](int v, int pr){
        for (auto [i, w]: g[v]){
            if (i == pr) continue;
            b[i] = w - b[v];
            a[i] = -a[v];
            dfs(i, v);
        }
    };
    a[1] = 1; b[1] = 0;
    dfs(1, 0);

    double X = 0; bool ind = 1;
    for (auto [x, y, w]: ed){
        int p = a[x] + a[y], q = b[x] + b[y];
        if (!p){
            if (q != w){
                cout<<"NO"<<"\n";
                return 0;
            }
            continue;
        }
        if (ind){
            X = 1.0 * (w - q) / p;
            ind = 0;
            continue;
        }
        
        if (X != 1.0 * (w - q) / p){
            cout<<"NO"<<"\n";
            return 0;
        }
    }
    
    if (ind){
        vector<int> all;
        for (int i = 1; i <= n; i++){
            if (a[i] == -1){
                a[i] = -a[i];
                b[i] = -b[i];
            }
            all.pb(-b[i]);
        }
        
        sort(all.begin(), all.end());
        X = all[all.size() / 2];
    }

    cout<<"YES"<<"\n";
    for (int i = 1; i <= n; i++){
        cout<<a[i] * X + b[i]<<" ";
    }
    cout<<"\n";
}

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