oj.uz

Submission #305684

# Submission time Handle Problem Language Result Execution time Memory
305684 2020-09-23T19:29:04 Z ntfx timeismoney (balkan11_timeismoney) C++17
100 / 100
 851 ms 620 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;


const int N = 200, M = 1e4;
int n, m, A, B, sumT, sumC;
int t[M], c[M], mst[N];
int src[M], dst[M];
ll mn = 1e18;
pii ids[M];
int par[N];

struct DSU {
    void init() { forn(i, n) par[i] = i; }
    int find(int u) { return par[u] == u ? u : par[u] = find(par[u]); }
    bool join(int u, int v) {
        if ((u = find(u)) == (v = find(v))) return false;
        return par[v] = u, true;
    }
} dsu;

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) ids[i] = {a*t[i] + b*c[i], i};
    sort(ids, ids + m);
    sumT = 0, sumC = 0;
    int pos = 0;
    dsu.init();
    forn(i, m) {
        int id = ids[i].snd;
        if (dsu.join(src[id], dst[id]))
            sumT += t[id], sumC += c[id], mst[pos++] = id;
    }
    ll v = ll(sumT) * sumC;
    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;
    forn(i, m) cin >> src[i] >> dst[i] >> t[i] >> c[i];

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

    optimize(A, B); 
    cout << sumT << ' ' << sumC << endl;
    forn(i, n-1) cout << src[mst[i]] << ' ' << dst[mst[i]] << 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 1 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 0 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 512 KB Output is correct
9 Correct 0 ms 384 KB Output is correct
10 Correct 0 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 7 ms 384 KB Output is correct
15 Correct 4 ms 416 KB Output is correct
16 Correct 93 ms 384 KB Output is correct
17 Correct 97 ms 384 KB Output is correct
18 Correct 91 ms 384 KB Output is correct
19 Correct 845 ms 620 KB Output is correct
20 Correct 851 ms 616 KB Output is correct