Submission #1287926

#	Time	Username	Problem	Language	Result	Execution time	Memory
1287926		Hamed_Ghaffari	Graph (BOI20_graph)	C++20	0 / 100	2 ms	340 KiB

Graph

#include <bits/stdc++.h>
using namespace std;

using pii = pair<int, int>;

#define X first
#define Y second
#define SZ(x) int(x.size())
#define all(x) x.begin(), x.end()

const int MXN = 2e5+5;

int n, m, fr[MXN], to[MXN], w[MXN];
vector<int> g[MXN];
pii val[MXN];
bool vis[MXN], mark[MXN];

void dfs(int v) {
    vis[v] = 1;
    for(int i : g[v]) {
        int u = v^fr[i]^to[i];
        if(vis[u]) continue;
        val[u].X = -val[v].X;
        val[u].Y = -val[v].Y+w[i];
        mark[i] = 1;
        dfs(u);
    }
}

int32_t main() {
    cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(0);
    cin >> n >> m;
    for(int i=1; i<=m; i++) {
        cin >> fr[i] >> to[i] >> w[i]; w[i] *= 2;
        g[fr[i]].push_back(i);
        g[to[i]].push_back(i);
    }
    val[1] = {1, 0};
    dfs(1);
    bool fnd = 0;
    int x = -1;
    for(int i=1; i<=m; i++) if(!mark[i]) {
        if(val[fr[i]].X+val[to[i]].X) {
            int y = (w[i]-val[fr[i]].Y-val[to[i]].Y) / (val[fr[i]].X + val[to[i]].X);
            if(!fnd || (fnd && y==x)) {
                fnd = 1;
                x = y;
            }
            else {
                cout << "NO\n";
                return 0;
            }
        }
        else if(val[fr[i]].Y+val[to[i]].Y!=w[i]) {
            cout << "NO\n";
            return 0;
        }
    }
    cout << "YES\n";
    if(!fnd) {
        vector<int> vec;
        for(int i=1; i<=n; i++)
            vec.push_back(val[i].Y*(val[i].X==1 ? -1 : 1));
        sort(all(vec));
        x = vec[SZ(vec)/2];
    }
    for(int i=1; i<=n; i++) {
        int v = val[i].X*x + val[i].Y;
        if(v<0) cout << '-', v = -v;
        cout << v/2;
        if(v%2) cout << ".5";
        cout << ' ';
    }
    cout << '\n';
    return 0;
}

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