Submission #1278435

#	Time	Username	Problem	Language	Result	Execution time	Memory
1278435		Alebn	Graph (BOI20_graph)	C++20	0 / 100	1 ms	344 KiB

Graph

#include <bits/stdc++.h>
#define int long long
#define pii pair<int,int>
#define ff first
#define ss second
#define all(x) x.begin(),x.end()
using namespace std;

struct DSU {
    struct N {
        int p, sz = 1, c = 0, s = 0;
        N() {}
    };
    vector<N> d;
    DSU(int n) {
        d = vector<N>(n);
        for(int i = 0; i < n; i++) d[i].p = i;
    }
    int find(int i) {
        if(d[i].p == i) return i;
        d[i].p = find(d[i].p);
        d[i].c += d[d[i].p].c;
        d[i].s != d[d[i].p].s;
        return d[i].p;
    }
    bool join(int i, int j, int k) {
        int x = find(i), y = find(j);
        if(x == y) return true;
        if(d[x].sz < d[y].sz) swap(x, y);
        d[x].sz += d[y].sz;
        d[y].p = x;
        d[y].c += k - d[i].c - d[j].c;
        d[y].s = !d[i].s != d[j].s;
        return false;
    }
};
struct E {
    int a, b, c;
    E(int ai, int bi, int ci):a(ai),b(bi),c(ci){}
    E(){}
};

signed main() {
    cout << fixed << setprecision(8);
    int n, m, a, b, c;
    cin >> n >> m;
    DSU d(n);
    vector<E> edges;
    for(int i = 0; i < m; i++) {
        cin >> a >> b >> c;
        if(d.join(--a, --b, c)) edges.push_back(E(a, b, c));
    }
    vector<double> res(n, INT_MAX);
    bool ok = true;
    for(auto [a, b, c] : edges) {
        if(d.d[a].s == d.d[b].s) res[d.find(a)] = (d.d[a].s ? -1.f : 1.f) * (c - d.d[a].c - d.d[b].c) / 2.f;
        else if(c - d.d[a].c - d.d[b].c) {
            ok = false;
            break;
        }
    }
    if(!ok) {
        cout << "NO\n";
        return 0;
    }
    cout << "YES\n";
    map<int,pii> mp;
    for(int i = 0; i < n; i++) {
        a = d.find(i);
        if(res[a] == INT_MAX) {
            if(d.d[i].s) mp[a].ss++;
            else mp[a].ff++;
        }
    }
    for(auto i : mp) {
        if(i.ss.ff < i.ss.ss) res[i.ff] = 1;
        else res[i.ff] = 0;
    }
    for(int i = 0; i < n; i++) {
        a = d.find(i);
        res[i] = (d.d[i].s ? -1.f : 1.f) * res[a] + d.d[i].c;
        cout << res[i] << " ";
    }
    cout << "\n";
}

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