Submission #631858

#	Time	Username	Problem	Language	Result	Execution time	Memory
631858		ziduo	Travelling Merchant (APIO17_merchant)	C++14	100 / 100	113 ms	4156 KiB

merchant

#include <bits/stdc++.h>
#define FOR(i, x, y) for (int i = x; i < y; i++)
typedef long long ll;
using namespace std;
 
const ll INF = LLONG_MAX / 2;
 
int n, m, x;
ll b[101][1001], s[101][1001];
ll graph[101][101], profit[101][101], graph2[101][101];
 
void floyd_warshall(ll adj[101][101]) {
	FOR(i, 1, n + 1)
		FOR(j, 1, n + 1)
			FOR(k, 1, n + 1)
				adj[j][k] = min(adj[j][k], adj[j][i] + adj[i][k]);
}
 
int main() {
	iostream::sync_with_stdio(false);
	cin.tie(0);
	cin >> n >> m >> x;
	FOR(i, 1, n + 1) {
		FOR(j, 1, n + 1) graph[i][j] = INF;
		FOR(j, 1, x + 1) cin >> b[i][j] >> s[i][j];
	}
	FOR(i, 0, m) {
		int u, v, w;
		cin >> u >> v >> w;
		graph[u][v] = w;
	}
	floyd_warshall(graph);
	FOR(i, 1, n + 1) FOR(j, 1, n + 1) FOR(k, 1, x + 1)
		if (s[j][k] != -1 && b[i][k] != -1)
			profit[i][j] = max(profit[i][j], s[j][k] - b[i][k]);
 
	ll l = 1, r = 1e9;
	while (l <= r) {
		ll mid = (l + r) / 2;
		FOR(i, 1, n + 1) FOR(j, 1, n + 1)
			graph2[i][j] = mid * min(graph[i][j], INF / mid) - profit[i][j];
		floyd_warshall(graph2);
		bool has_nonnegative_cycle = false;
		FOR(i, 1, n + 1) if (graph2[i][i] <= 0) has_nonnegative_cycle = true;
		if (has_nonnegative_cycle) l = mid + 1;
		else r = mid - 1;
	}
	cout << r;
	return 0;
}

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