Submission #57347

#	Time	Username	Problem	Language	Result	Execution time	Memory
57347		gabrielsimoes	Travelling Merchant (APIO17_merchant)	C++17	0 / 100	140 ms	2004 KiB

merchant

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

typedef pair<int, int> pii;
typedef long long ll;
const int MAXN = 101, MAXM = 9901, MAXK = 1001;
const ll INF = 1e18;
// const ll INF = 1000;
int N, M, K;
vector<pii> g[MAXN];
ll buy[MAXN][MAXK];
ll sell[MAXN][MAXK];

ll d[MAXN][MAXN];
ll gain[MAXN][MAXN];
ll dist[MAXN];
bool ok[MAXN];

bool testPosCycle(ll x) {
    // for (int i = 1; i <= N; i++) dist[i] = INF;
    memset(ok, 0, sizeof(ok));
    dist[1] = 0;
    ok[1] = true;

    for (int cnt = 0; cnt <= N; cnt++) {
        for (int i = 1; i <= N; i++) {
            if (!ok[i]) continue;
            for (int j = 1; j <= N; j++) {
                if (i == j) continue;

                ll dd = dist[i] + gain[i][j] - x*d[i][j];

                if (!ok[j] || dd > dist[j]) {
                    dist[j] = dd;
                    ok[j] = true;
                }

                if (i != 1 && j == 1 && dd >= 0)
                    return true;
            }
        }
    }

    // for (int i = 1; i <= N; i++) {
    //     printf("x %d i %d dist %lld\n", x, i, dist[i]);
    // }

    return false;
}

int main() {
    scanf("%d%d%d", &N, &M, &K);
    for (int i = 1; i <= N; i++) {
        for (int k = 1; k <= K; k++) {
            scanf("%lld%lld", &buy[i][k], &sell[i][k]);
        }
    }

    for (int i = 1; i <= N; i++) {
        for (int k = 1; k <= N; k++) {
            d[i][k] = INF;
        }
        d[i][i] = 0;
    }

    for (int i = 1,a,b,c; i <= M; i++) {
        scanf("%d%d%d", &a, &b, &c);
        g[a].push_back({b, c});
        d[a][b] = c;
    }

    for (int k = 1; k <= N; k++) {
        for (int i = 1; i <= N; i++) {
            for (int j = 1; j <= N; j++) {
                d[i][j] = min(d[i][j], d[i][k] + d[k][j]);
            }
        }
    }

    for (int i = 1; i <= N; i++) {
        for (int j = 1; j <= N; j++) {
            for (int k = 1; k <= K; k++) {
                if (buy[i][k] != -1 && sell[j][k] != -1) {
                    gain[i][j] = max(gain[i][j], -buy[i][k] + sell[j][k]);
                }
            }
        }
    }

    ll l = 0, r = INF;
    while (l < r) {
        ll m = (l + r + 1LL) >> 1;
        if (testPosCycle(m)) l = m;
        else r = m-1;
    }

    printf("%lld\n", l);
}

Compilation message (stderr)

merchant.cpp: In function 'int main()':
merchant.cpp:52:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d", &N, &M, &K);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~
merchant.cpp:55:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%lld%lld", &buy[i][k], &sell[i][k]);
             ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
merchant.cpp:67:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d%d", &a, &b, &c);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~

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