Submission #128399

#	Time	Username	Problem	Language	Result	Execution time	Memory
128399		keko37	Travelling Merchant (APIO17_merchant)	C++14	66 / 100	168 ms	3064 KiB

merchant

#include<bits/stdc++.h>

using namespace std;

typedef long long llint;

const int MAXN = 105;
const int MAXP = 1005;
const llint INF = 3000000000000000LL;

llint n, m, p;
llint buy[MAXN][MAXP], sell[MAXN][MAXP];
llint d[MAXN][MAXN], g[MAXN][MAXN];
llint cost[MAXN][MAXN];

bool moze (llint t) {
    if (t == 0) return 1;
    for (int i=1; i<=n; i++) {
        for (int j=1; j<=n; j++) {
            cost[i][j] = t * d[i][j] - g[i][j];
            if (d[i][j] == INF) cost[i][j] = INF;
        }
    }
    for (int k=1; k<=n; k++) {
        for (int i=1; i<=n; i++) {
            for (int j=1; j<=n; j++) {
                if (cost[i][k] + cost[k][j] < cost[i][j]) {
                    cost[i][j] = cost[i][k] + cost[k][j];
                }
                if (cost[i][j] < -INF) cost[i][j] = -INF;
            }
        }
    }
    for (int i=1; i<=n; i++) {
        if (cost[i][i] <= 0) return 1;
    }
    return 0;
}

void precompute () {
    for (int k=1; k<=n; k++) {
        for (int i=1; i<=n; i++) {
            for (int j=1; j<=n; j++) {
                if (d[i][k] + d[k][j] < d[i][j]) {
                    d[i][j] = d[i][k] + d[k][j];
                }
            }
        }
    }
    for (int i=1; i<=n; i++) {
        for (int j=1; j<=n; j++) {
            llint res = 0;
            for (int k=1; k<=p; k++) {
                res = max(res, sell[j][k] - buy[i][k]);
            }
            g[i][j] = res;
        }
    }
}

int main () {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cin >> n >> m >> p;
    for (int i=1; i<=n; i++) {
        for (int j=1; j<=p; 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] = -INF;
        }
    }
    for (int i=1; i<=n; i++) {
        for (int j=1; j<=m; j++) {
            d[i][j] = INF;
        }
    }
    for (int i=1; i<=m; i++) {
        int a, b, c;
        cin >> a >> b >> c;
        d[a][b] = c;
    }
    precompute();
    llint lo = 0, hi = 1000000005;
    while (lo < hi) {
        llint mid = (lo + hi + 1) / 2;
        if (moze(mid)) {
            lo = mid;
        } else {
            hi = mid-1;
        }
    }
    cout << lo;
    return 0;
}

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