Submission #231936

#	Time	Username	Problem	Language	Result	Execution time	Memory
231936		ruler	Travelling Merchant (APIO17_merchant)	C++14	100 / 100	113 ms	3320 KiB

merchant

// IOI 2021
#include <bits/stdc++.h>
using namespace std;

#define endl '\n'
#define ends ' '
#define die(x) return cout << x << endl, 0
#define all(v) v.begin(), v.end()
#define sz(x) (int)(x.size())
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) { cerr << ends << H; debug_out(T...); }
#define debug(...) cerr << "{" << #__VA_ARGS__ << "}:", debug_out(__VA_ARGS__)
typedef long long ll;
typedef pair<int, int> pii;
const int INF = 2e9;
const ll MOD = 1e9 + 7;
 
////////////////////////////////////////////////////////////////////

const int N = 1e2 + 5, K = 1e3 + 5;

int n, m, t, B[N][K], S[N][K], D[N][N], V[N][N];
ll C[N][N];

bool OK(int q) {
	for (int i = 1; i <= n; i++) for (int j = 1; j <= n; j++) C[i][j] = 1LL * q * D[i][j] - V[i][j];
	for (int k = 1; k <= n; k++) for (int i = 1; i <= n; i++) for (int j = 1; j <= n; j++) if (i ^ j) C[i][j] = min(C[i][j], C[i][k] + C[k][j]);
	for (int i = 1; i <= n; i++) for (int j = 1; j <= n; j++) if (i != j && C[i][j] + C[j][i] <= 0) return true;
	return false;
}

int main() {

	ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	mt19937 Rnd(time(0));

	memset(D, 63, sizeof D);

	cin >> n >> m >> t;
	for (int i = 1; i <= n; i++) for (int j = 1; j <= t; j++) cin >> B[i][j] >> S[i][j];
	for (int i = 1; i <= m; i++) {
		int v, u, w; cin >> v >> u >> w;
		D[v][u] = min(D[v][u], w);
	}
	for (int i = 1; i <= n; i++) D[i][i] = 0;
	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 <= t; k++) if (B[i][k] != -1 && S[j][k] != -1) V[i][j] = max(V[i][j], S[j][k] - B[i][k]);

	int dw = 0, up = INF;
	while (up - dw > 1) {
		int md = (dw + up) >> 1;
		if (OK(md)) dw = md;
		else up = md;
	}
	cout << dw << endl;

	return 0;
}

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