Submission #1251944

#	Time	Username	Problem	Language	Result	Execution time	Memory
1251944		CodeLakVN	Travelling Merchant (APIO17_merchant)	C++20	0 / 100	80 ms	1344 KiB

merchant

#include <bits/stdc++.h>
using namespace std;

#define task "main"
#define F first
#define S second
#define ii pair<int, int>
#define il pair<int, long long>
#define li pair<long long, int>
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FOD(i, b, a) for(int i = (b); i >= (a); --i)

template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }

template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }

template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }

const int MAX_N = 102;
const int MAX_M = 9902;
const int MAX_K = 1002;

int nNode, nEdge, nItem;
vector<ii> adj[MAX_N];
int buy[MAX_K][MAX_N], sell[MAX_K][MAX_N];
int maxProfit[MAX_N][MAX_N]; // maxProfit[i][j]: maximum profit when buy an item at market i and sell it at market j

long long dist[MAX_N][MAX_N];

void floyd() {
    memset(dist, 0x3f, sizeof(dist));
    FOR(u, 1, nNode) for (ii e : adj[u])
        dist[u][e.F] = e.S;

    FOR(k, 1, nNode) FOR(u, 1, nNode) FOR(v, 1, nNode) if (u != v) {
        minimize(dist[u][v], dist[u][k] + dist[k][v]);
    }
}

void findMaxProfit() {
    memset(maxProfit, 0, sizeof(maxProfit));
    FOR(i, 1, nNode) FOR(j, 1, nNode) if (i != j) FOR(item, 1, nItem)
        if (buy[item][i] != -1 && sell[item][j] != -1)
            maximize(maxProfit[i][j], -buy[item][i] + sell[item][j]);
}

long long dp[MAX_N];

bool valid(long long val) {
    bool ok = false;
    FOR(s, 1, nNode) { // starting node
        memset(dp, -0x3f, sizeof(dp));
        dp[s] = 0;
        FOR(u, 1, nNode) {
            if (u == s) continue;
            FOR(v, 1, nNode) if (v != u) {
                maximize(dp[u], dp[v] + maxProfit[v][u] - dist[v][u] * val);
            }
        }

        long long res = LLONG_MIN;
        FOR(u, 1, nNode) if (u != s)
            maximize(res, dp[u] + maxProfit[u][s] - dist[u][s] * val);
        if (res >= 0) ok = true;
    }
    return ok;
}

void solve() {
    cin >> nNode >> nEdge >> nItem;
    FOR(i, 1, nNode) FOR(j, 1, nItem)
        cin >> buy[j][i] >> sell[j][i];
    FOR(i, 1, nEdge) {
        int u, v, w;
        cin >> u >> v >> w;
        adj[u].push_back({v, w});
    }

    floyd();
    findMaxProfit();

    long long l = 0, r = (long long)1e18, res = 0;
    while (l <= r) {
        long long mid = (l + r) >> 1;
        if (valid(mid)) l = (res = mid) + 1;
        else r = mid - 1;
    }

    cout << res << "\n";
}

int32_t main() {
    if (fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    bool multitest = 0;
    int numTest = 1;
    if (multitest) cin >> numTest;

    while (numTest--) {
        solve();
    }

    return 0;
}

/* Lak lu theo dieu nhac!!!! */

Compilation message (stderr)

merchant.cpp: In function 'int32_t main()':
merchant.cpp:106:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  106 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
merchant.cpp:107:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  107 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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