oj.uz

Submission #289736

# Submission time Handle Problem Language Result Execution time Memory
289736 2020-09-03T01:05:29 Z ntfx timeismoney (balkan11_timeismoney) C++17
100 / 100
 886 ms 1016 KB 
/*
    Problem: https://oj.uz/problem/view/balkan11_timeismoney

    Solution: http://www.boi2011.ro/resurse/tasks/timeismoney-sol.pdf
*/
#include <bits/stdc++.h>
using namespace std;

#ifdef LOCAL
    #define D(a) cerr << #a << " = " << a << endl
#else 
    #define D(a) 8 
#endif
#define fastio ios_base::sync_with_stdio(0); cin.tie(0)
#define dforsn(i,s,n) for(int i=int(n-1);i>=int(s);i--)
#define forsn(i,s,n) for(int i=int(s);i<int(n);i++)
#define all(a) (a).begin(),(a).end()
#define dforn(i,n) dforsn(i,0,n)
#define forn(i,n) forsn(i,0,n)
#define si(a) int((a).size())
#define pb emplace_back
#define mp make_pair
#define snd second
#define fst first
#define endl '\n'
using pii = pair<int,int>;
using vi = vector<int>;
using ll = long long;

struct UF {
    vi par, sz;
    UF(int n): par(n), sz(n, 1) { iota(all(par), 0); }
    int find(int u) { return par[u] == u ? u : par[u] = find(par[u]); }
    bool connected(int u, int v) { return find(u) == find(v); }
    bool join(int u, int v) {
        if (connected(u, v)) return false;
        u = find(u), v = find(v);
        if (sz[u] < sz[v]) par[u] = v, sz[v] += sz[u];
        else par[v] = u, sz[u] += sz[v];
        return true;
    }
};

vi mst;
ll mn = 1e18;
int n, m, A, B, sumT, sumC;
vector<tuple<int,int,int,int>> edges;

struct Kruskal {
    vector<pii> ids;
    void addEdge(int cost, int id) { ids.pb(cost, id); }
    ll build() {
        sort(all(ids));
        mst.clear();
        UF uf(n);
        sumT = 0, sumC = 0;
        for (auto &[cst, id] : ids) {
            auto &[u, v, t, c] = edges[id];
            if (uf.join(u, v))
                mst.pb(id), sumT += t, sumC += c;
        }
        ids.clear();
        return sumT * sumC;
    }
} kruskal;

struct Point {
    int x, y;
    bool collinear(const Point &p1, const Point &p2) {
        return ll(p2.y - p1.y) * (x - p1.x) == ll(y - p1.y) * (p2.x - p1.x);
    }
};

// Minimize a * sumT + b * sumC = v
Point optimize(int a, int b) { 
    forn(i, m) {
        auto &[u, v, t, c] = edges[i];
        kruskal.addEdge(a*t + b*c, i);
    }
    ll v = kruskal.build();
    if (v < mn) mn = v, A = a, B = b;
    return {sumC, sumT};
}

void computeConvexHull(const Point &p1, const Point &p2) {
    Point p = optimize(p2.x - p1.x, p1.y - p2.y);
    if (p.collinear(p1, p2)) return;
    computeConvexHull(p1, p), computeConvexHull(p, p2);
}

int main() {
    fastio;

    cin >> n >> m;
    edges.resize(m);
    for (auto &[u, v, t, c] : edges)
        cin >> u >> v >> t >> c;

    computeConvexHull(optimize(0, 1), optimize(1, 0));

    optimize(A, B); 
    cout << sumT << ' ' << sumC << endl;
    for (int id : mst) {
        auto &[u, v, t, c] = edges[id];
        cout << u << ' ' << v << endl;
    }
    return 0;
}

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 1 ms 384 KB Output is correct
5 Correct 1 ms 384 KB Output is correct
6 Correct 1 ms 384 KB Output is correct
7 Correct 2 ms 384 KB Output is correct
8 Correct 7 ms 896 KB Output is correct
9 Correct 1 ms 384 KB Output is correct
10 Correct 1 ms 384 KB Output is correct
11 Correct 1 ms 384 KB Output is correct
12 Correct 1 ms 384 KB Output is correct
13 Correct 1 ms 384 KB Output is correct
14 Correct 6 ms 384 KB Output is correct
15 Correct 4 ms 384 KB Output is correct
16 Correct 94 ms 384 KB Output is correct
17 Correct 102 ms 384 KB Output is correct
18 Correct 95 ms 384 KB Output is correct
19 Correct 864 ms 1016 KB Output is correct
20 Correct 886 ms 896 KB Output is correct