Submission #213531

#	Time	Username	Problem	Language	Result	Execution time	Memory
213531		tri	Travelling Merchant (APIO17_merchant)	C++14	100 / 100	249 ms	4564 KiB

merchant

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;

#define pb push_back
#define f first
#define s second

namespace debug {
    const int DEBUG = true;

    template<class T1, class T2>
    void pr(const pair<T1, T2> &x);

    template<class T, size_t SZ>
    void pr(const array<T, SZ> &x);

    template<class T>
    void pr(const vector<T> &x);

    template<class T>
    void pr(const set<T> &x);

    template<class T1, class T2>
    void pr(const map<T1, T2> &x);

    template<class T>
    void pr(const T &x) { if (DEBUG) cout << x; }

    template<class T, class... Ts>
    void pr(const T &first, const Ts &... rest) { pr(first), pr(rest...); }

    template<class T1, class T2>
    void pr(const pair<T1, T2> &x) { pr("{", x.f, ", ", x.s, "}"); }

    template<class T>
    void prIn(const T &x) {
        pr("{");
        bool fst = 1;
        for (auto &a : x) {
            pr(fst ? "" : ", ", a), fst = 0;
        }
        pr("}");
    }

    template<class T, size_t SZ>
    void pr(const array<T, SZ> &x) { prIn(x); }

    template<class T>
    void pr(const vector<T> &x) { prIn(x); }

    template<class T>
    void pr(const set<T> &x) { prIn(x); }

    template<class T1, class T2>
    void pr(const map<T1, T2> &x) { prIn(x); }

    void ps() { pr("\n"), cout << flush; }

    template<class Arg, class... Args>
    void ps(const Arg &first, const Args &... rest) {
        pr(first, " ");
        ps(rest...);
    }
}
using namespace debug;


const int MAXN = 105;
const int MAXK = 1005;
const ll INF = 1e12;

ll aM[MAXN][MAXN];

ll trans[2][MAXN][MAXK]; // 0 is buy 1 is sell

ll prof[MAXN][MAXN];

ld agg[MAXN][MAXN];

ld best[MAXN];

int N, M, K;

bool pos(ld ef) {
    assert(ef > 0);
//    ps(ef);
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            agg[i][j] = prof[i][j] - aM[i][j] * ef;
        }
    }

    fill(best, best + MAXN, 0);

    for (int i = 0; i < N; i++) {
        for (int cV = 0; cV < N; cV++) {
            for (int aV = 0; aV < N; aV++) {
                if (best[aV] < best[cV] + agg[cV][aV]) {
                    best[aV] = best[cV] + agg[cV][aV];
                }
            }
        }
    }

    for (int cV = 0; cV < N; cV++) {
        for (int aV = 0; aV < N; aV++) {
            if (best[aV] < best[cV] + agg[cV][aV]) {
                return true;
            }
        }
    }
    return false;
}

ll binSearch() {
    ll low = 0;
    ll hi = INF;
    while (low != hi) {
        ll mid = (low + hi + 1) / 2;
        if (pos(mid)) {
            low = mid;
        } else {
            hi = mid - 1;
        }
    }

    if (pos(low + 1 - 1e-10L)) {
        return low + 1;
    }

    return low;
}

int main() {
//    freopen("travelling.in", "r", stdin);

    ios_base::sync_with_stdio(false);
    cin.tie(NULL);


    cin >> N >> M >> K;
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < K; j++) {
            cin >> trans[0][i][j] >> trans[1][i][j];
            if (trans[0][i][j] == -1) {
                trans[0][i][j] = INF;
            }
            if (trans[1][i][j] == -1) {
                trans[1][i][j] = -INF;
            }
        }
    }

    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            aM[i][j] = INF;
        }
    }

//    ps("here");

    for (int i = 0; i < M; i++) {
        int u, v;
        ll c;
        cin >> u >> v >> c;
        u--, v--;
        aM[u][v] = c;
    }

    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            for (int k = 0; k < N; k++) {
                if (aM[j][i] + aM[i][k] < aM[j][k]) {
                    aM[j][k] = aM[j][i] + aM[i][k];
                }
            }
        }
    }

    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            ll cM = 0;
            for (int k = 0; k < K; k++) {
                cM = max(cM, trans[1][j][k] - trans[0][i][k]);
            }
            prof[i][j] = cM;
        }
    }

//    cout << pos(2) << endl;

    ll ans = binSearch();
    cout << ans << endl;
}

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