#include "bits/stdc++.h" using namespace std; #define rep(i, b, e) for(int i = (b); i <= (e); i++) #define per(i, b, e) for(int i = (e); i >= (b); i--) #define FOR(i, b, e) rep(i, b, (e) - 1) #define SZ(x) int(x.size()) #define all(x) x.begin(), x.end() #define pb push_back #define mp make_pair #define st first #define nd second using ll = long long; using vi = vector<int>; using pii = pair<int, int>; auto &operator<<(auto &o, pair<auto, auto> p) { return o << "(" << p.st << ", " << p.nd << ")"; } auto operator<<(auto &o, auto x)->decltype(end(x), o) { o << "{"; int i=0; for(auto e: x) o << ", " + 2*!i++ << e; return o << "}"; } #ifdef LOCAL #define deb(x...) cerr << "[" #x "]: ", [](auto...$) { \ ((cerr << $ << "; "),...) << endl; }(x) #else #define deb(...) #endif const int SQ = 35'000; vector<vi> getLewa(vector<vector<pii>> &G, vi &p) { int n = SZ(G); vector<vi> vis(n, vi(SQ)); queue<pii> q; vis[0][1] = 1; q.push({0, 1}); while(!q.empty()) { auto [v, moc] = q.front(); q.pop(); for(auto &[u, boost]: G[v]) { ll nowa = ll(moc) * boost; if(nowa < SQ && !vis[u][nowa] && nowa <= p[u]) { vis[u][nowa] = 1; q.push({u, nowa}); } } } vector<vi> good(n); FOR(i, 0, n) FOR(j, 0, SQ) if(vis[i][j]) good[i].pb(j); return good; } vector<vi> getPrawa(vector<vector<pii>> &G, vi &p) { int n = SZ(G); vector<vector<pii>> GR(n); FOR(v, 0, n) for(auto &[u, boost]: G[v]) GR[u].pb({v, boost}); vector<vi> dist(n, vi(SQ)); priority_queue<tuple<int, int, int>> q; dist[n - 1][1] = p[n - 1]; q.push({p[n - 1], n - 1, 1}); while(!q.empty()) { auto [lim, v, moc] = q.top(); q.pop(); for(auto &[u, boost]: GR[v]) { int nlim = min(lim / boost, p[u]); ll nmoc = ll(moc) * boost; if(nmoc < SQ && dist[u][nmoc] < nlim) { dist[u][nmoc] = nlim; q.push({nlim, u, nmoc}); } } } return dist; } void solve() { int n, m; cin >> n >> m; vector<vector<pii>> G(n); vi p(n); for(auto &x: p) cin >> x; FOR(i, 0, m) { int a, b, c; cin >> a >> b >> c; a--, b--; G[a].pb({b, c}); } auto lewa = getLewa(G, p); auto prawa = getPrawa(G, p); int ans = (n == 1 ? 1 : -1); FOR(v, 0, n) for(auto &[u, moc]: G[v]) { FOR(boost, 1, SQ) { int bound = prawa[u][boost] / moc; auto it = upper_bound(all(lewa[v]), bound); if(it == lewa[v].begin()) continue; int zlewo = *prev(it); ans = max(ans, zlewo * moc * boost); } } cout << ans << '\n'; } int main() { cin.tie(0)->sync_with_stdio(0); int tt = 1; cin >> tt; FOR(te, 0, tt) solve(); return 0; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 | #include "bits/stdc++.h" using namespace std; #define rep(i, b, e) for(int i = (b); i <= (e); i++) #define per(i, b, e) for(int i = (e); i >= (b); i--) #define FOR(i, b, e) rep(i, b, (e) - 1) #define SZ(x) int(x.size()) #define all(x) x.begin(), x.end() #define pb push_back #define mp make_pair #define st first #define nd second using ll = long long; using vi = vector<int>; using pii = pair<int, int>; auto &operator<<(auto &o, pair<auto, auto> p) { return o << "(" << p.st << ", " << p.nd << ")"; } auto operator<<(auto &o, auto x)->decltype(end(x), o) { o << "{"; int i=0; for(auto e: x) o << ", " + 2*!i++ << e; return o << "}"; } #ifdef LOCAL #define deb(x...) cerr << "[" #x "]: ", [](auto...$) { \ ((cerr << $ << "; "),...) << endl; }(x) #else #define deb(...) #endif const int SQ = 35'000; vector<vi> getLewa(vector<vector<pii>> &G, vi &p) { int n = SZ(G); vector<vi> vis(n, vi(SQ)); queue<pii> q; vis[0][1] = 1; q.push({0, 1}); while(!q.empty()) { auto [v, moc] = q.front(); q.pop(); for(auto &[u, boost]: G[v]) { ll nowa = ll(moc) * boost; if(nowa < SQ && !vis[u][nowa] && nowa <= p[u]) { vis[u][nowa] = 1; q.push({u, nowa}); } } } vector<vi> good(n); FOR(i, 0, n) FOR(j, 0, SQ) if(vis[i][j]) good[i].pb(j); return good; } vector<vi> getPrawa(vector<vector<pii>> &G, vi &p) { int n = SZ(G); vector<vector<pii>> GR(n); FOR(v, 0, n) for(auto &[u, boost]: G[v]) GR[u].pb({v, boost}); vector<vi> dist(n, vi(SQ)); priority_queue<tuple<int, int, int>> q; dist[n - 1][1] = p[n - 1]; q.push({p[n - 1], n - 1, 1}); while(!q.empty()) { auto [lim, v, moc] = q.top(); q.pop(); for(auto &[u, boost]: GR[v]) { int nlim = min(lim / boost, p[u]); ll nmoc = ll(moc) * boost; if(nmoc < SQ && dist[u][nmoc] < nlim) { dist[u][nmoc] = nlim; q.push({nlim, u, nmoc}); } } } return dist; } void solve() { int n, m; cin >> n >> m; vector<vector<pii>> G(n); vi p(n); for(auto &x: p) cin >> x; FOR(i, 0, m) { int a, b, c; cin >> a >> b >> c; a--, b--; G[a].pb({b, c}); } auto lewa = getLewa(G, p); auto prawa = getPrawa(G, p); int ans = (n == 1 ? 1 : -1); FOR(v, 0, n) for(auto &[u, moc]: G[v]) { FOR(boost, 1, SQ) { int bound = prawa[u][boost] / moc; auto it = upper_bound(all(lewa[v]), bound); if(it == lewa[v].begin()) continue; int zlewo = *prev(it); ans = max(ans, zlewo * moc * boost); } } cout << ans << '\n'; } int main() { cin.tie(0)->sync_with_stdio(0); int tt = 1; cin >> tt; FOR(te, 0, tt) solve(); return 0; } |