Submission #545948

#	Time	Username	Problem	Language	Result	Execution time	Memory
545948		Monarchuwu	Travelling Merchant (APIO17_merchant)	C++17	100 / 100	154 ms	3316 KiB

merchant

#include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;
using namespace std;

const int N = 100 + 2, M = 9900 + 4, K = 1000 + 3, inf = 1e9 + 7;
const ll inf2 = 1.1e18;
int n, m, k;
int b[N][K], s[N][K];
ll d[N][N];

int w[N][N];
void prep() {
    for (int i = 1; i <= n; ++i)
        for (int j = 1; j <= n; ++j)
            for (int kk = 0; kk < k; ++kk) if (~b[i][kk] && ~s[j][kk])
                w[i][j] = max(w[i][j], s[j][kk] - b[i][kk]);

    for (int kk = 1; kk <= n; ++kk)
        for (int i = 1; i <= n; ++i)
            for (int j = 1; j <= n; ++j)
                d[i][j] = min(d[i][j], d[i][kk] + d[kk][j]);
}

ll dist[N][N];
void maxi(ll &a, ll b) { if (a < b) a = b; }
bool check(ll x) {
    for (int i = 1; i <= n; ++i)
        for (int j = 1; j <= n; ++j) {
            if (i == j || d[i][j] == inf) dist[i][j] = -inf2;
            else dist[i][j] = w[i][j] - d[i][j] * x;
        }

    for (int kk = 1; kk <= n; ++kk)
        for (int i = 1; i <= n; ++i)
            for (int j = 1; j <= n; ++j)
                maxi(dist[i][j], dist[i][kk] + dist[kk][j]);

    for (int i = 1; i <= n; ++i)
        if (dist[i][i] >= 0) return true;
    return false;
}

int main() {
    cin.tie(NULL)->sync_with_stdio(false);
    cin >> n >> m >> k;
    for (int i = 1; i <= n; ++i)
        for (int j = 0; j < k; ++j)
            cin >> b[i][j] >> s[i][j];

    for (int i = 1; i <= n; ++i)
        for (int j = 1; j < i; ++j) d[i][j] = d[j][i] = inf;
    for (int i = 0, a, b; i < m; ++i) {
        cin >> a >> b;
        cin >> d[a][b];
    }
    prep();

    int lo(0), hi(inf), mid;
    while (lo <= hi) {
        mid = (lo + hi) >> 1;
        if (check(mid))
            lo = mid + 1;
        else hi = mid - 1;
    }
    cout << lo - 1 << '\n';
}
/**  /\_/\
 *  (= ._.)
 *  / >0  \>1
**/

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