제출 #501128

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
501128		Stickfish	여행하는 상인 (APIO17_merchant)	C++17	0 / 100	115 ms	3408 KiB

merchant

#include <iostream>
#include <cassert>
#include <vector>
using namespace std;
using ll = long long;

const ll INF = 1.77013e15;
const int MAXN = 100;
const int MAXK = 1000;
ll buy[MAXN][MAXK];
ll sell[MAXN][MAXK];
vector<pair<int, ll>> edg[MAXN];
vector<pair<int, ll>> redg[MAXN];
ll d[MAXN][MAXN];
ll prof[MAXN][MAXN];

ll smoke[MAXN][MAXN];
ll immortal[MAXN][MAXN];

signed main() {
    int n, m, k;
    cin >> n >> m >> k;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < k; ++j) {
            cin >> buy[i][j] >> sell[i][j];
            if (buy[i][j] == -1)
                buy[i][j] = INF;
            if (sell[i][j] == -1)
                sell[i][j] = 0;
        }
    }
    for (int i = 0; i < m; ++i) {
        int u, v, w;
        cin >> u >> v >> w;
        --u, --v;
        edg[u].push_back({v, w});
        edg[v].push_back({u, w});
    }
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            d[i][j] = INF;
        }
        d[i][i] = 0;
        for (auto [v, dv] : edg[i]) {
            d[i][v] = dv;
        }
    }
    for (int i = 0; i < n; ++i) {
        for (int v = 0; v < n; ++v) {
            for (int u = 0; u < n; ++u) {
                d[v][u] = min(d[v][u], d[v][i] + d[i][u]);
            }
        }
    }
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            for (int w = 0; w < n; ++w) {
                assert(d[i][j] + d[j][w] >= d[i][w]);
            }
        }
    }
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            for (int t = 0; t < k; ++t) {
                prof[i][j] = max(prof[i][j], sell[j][t] - buy[i][t]);
            }
        }
        assert(prof[i][i] == 0);
    }
    ll lb = 0, ub = INF;
    while (ub - lb > 1) {
        ll mb = (lb + ub) / 2;
        // (sum prof) / (sum time) >= mb
        // sum prof >= mb * (sum time)
        // sum {prof - mb * time} >= 0
        for (int i = 0; i < n; ++i) {
            for (int j = 0; j < n; ++j) {
                if (d[i][j] == INF || prof[i][j] == 0)
                    smoke[i][j] = -INF;
                else
                    smoke[i][j] = prof[i][j] - mb * d[i][j];
                immortal[i][j] = smoke[i][j];
            }
        }
        for (int i = 0; i < n; ++i) {
            for (int v = 0; v < n; ++v) {
                for (int u = 0; u < n; ++u) {
                    immortal[v][u] = max(immortal[v][u], immortal[v][i] + immortal[i][u]);
                }
            }
        }
        for (int i = 0; i < n; ++i) {
            if (immortal[i][i] > 0) {
                lb = mb;
            }
        }
        if (lb != mb)
            ub = mb;
    }
    cout << lb << endl;
}

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