Submission #412743

#	Time	Username	Problem	Language	Result	Execution time	Memory
412743		fvogel499	Travelling Merchant (APIO17_merchant)	C++14	0 / 100	225 ms	34524 KiB

merchant

/*
File created on 05/27/2021 at 13:38:24.
Link to problem: https://oj.uz/problem/view/APIO17_merchant
Description: plotting a graph then running binary search and executing floyd warshall's algorithm
Time complexity: O(N^3)
Space complexity: O(N^2)
Status: DEV
Copyright: Ⓒ 2021 Francois Vogel
*/

#include <iostream>
#include <cmath>
#include <vector>
#include <bitset>
#include <queue>
#include <cstring>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
#include <algorithm>

using namespace std;

#define mp pair<pii, pii>
#define pii pair<int, int>
#define f first
#define s second

#define int ll
#define ll long long

const int inf = 1e9;

int n;
vector<mp> edges;
int maxM = -1;

void bs(int start, int end) {
    if (start <= end) {
        int mid = (start+end)/2;
        int dist [n][n];
        for (int i = 0; i < n; i++) for (int j = 0; j < n; j++) dist[i][j] = inf;
        for (mp e : edges) dist[e.f.f][e.f.s] = min(dist[e.f.f][e.f.s], e.s.f*mid-e.s.s);
        for (int k = 0; k < n; k++) for (int i = 0; i < n; i++) for (int j = 0; j < n; j++) dist[i][j] = min(dist[i][j], dist[i][k]+dist[k][j]);
        bool negativeCycle = false;
        for (int i = 0; i < n; i++) if (dist[i][i] <= 0) negativeCycle = true;
        if (negativeCycle) {
            maxM = max(maxM, mid);
            bs(mid+1, end);
        }
        else bs(start, mid-1);
    }
}

signed main() {
    cin.tie(0);
    // ios_base::sync_with_stdio(0);

    int nbEdges, nbItems;
    cin >> n >> nbEdges >> nbItems;

    int buy [n][nbItems];
    int sell [n][nbItems];
    for (int i = 0; i < n; i++) for (int j = 0; j < nbItems; j++) cin >> buy[i][j] >> sell[i][j];

    int dist [n][n];
    for (int i = 0; i < n; i++) for (int j = 0; j < n; j++) dist[i][j] = inf;
    for (int i = 0; i < n; i++) dist[i][i] = 0;
    for (int i = 0; i < nbEdges; i++) {
        int u, v, t;
        cin >> u >> v >> t;
        u--;
        v--;
        dist[u][v] = min(dist[u][v], t);
    }
    for (int k = 0; k < n; k++) for (int i = 0; i < n; i++) for (int j = 0; j < n; j++) dist[i][j] = min(dist[i][j], dist[i][k]+dist[k][j]);

    for (int i = 0; i < n; i++) for (int j = 0; j < n; j++) for (int k = 0; k < nbItems; k++) {
        if (dist[i][j] != inf and buy[i][k] != -1 and sell[j][k] != -1) {
            mp e;
            e.f = pii(i, j);
            e.s = pii(dist[i][j], sell[j][k]-buy[i][k]);
            edges.push_back(e);
        }
    }

    bs(0, inf);

    cout << maxM+1;

    int d = 0;
    d++;
}

• Subtask 1: 0 / 12
• Subtask 2: 0 / 21
• Subtask 3: 0 / 33
• Subtask 4: 0 / 34