#include<bits/stdc++.h>
#define FOR(i,a,b) for(int i=a;i<(int)b;++i)
#define FORD(i,a,b) for(int i=a;i>=b;--i)
#define PB push_back
#define EB emplace_back
#define FI first
#define SE second
#define umap unordered_map
#define uset unordered_set
#define vi vector<int>
#define vvi vector<vi>
#define vll vector<ll>
#define vvll vector<vll>
#define vpii vector<pii>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define ALL(X) (X).begin(),(X).end()
#ifndef DEBUG
#define endl (char)10
#endif
using namespace std;
using ll = long long;
using ld = long double;
template <class T>
istream& operator>> (istream& is, vector<T>& vec){
FOR(i,0,vec.size()) is >> vec[i];
return is;
}
template <class T>
ostream& operator<< (ostream& os, vector<T>& vec){
for(auto& t : vec) os << t << " ";
return os;
}
template<class T, class U>
ostream& operator<< (ostream& os, const pair<T, U>& p){
os << p.FI << " " << p.SE;
return os;
}
template<class T, class U>
istream& operator>> (istream& is, pair<T, U>& p){
is >> p.FI >> p.SE;
return is;
}
bool is_solvable(vi& P, vector<vpii>& V) {
priority_queue<pair<int, int>> Q;
Q.emplace(-1, 0);
vi dist(V.size(), INT_MAX);
dist[0] = 1;
while(!Q.empty()) {
auto [d, v] = Q.top();
Q.pop();
d *= -1;
if(d != dist[v]) continue;
if (v == P.size() - 1) return true;
for(auto& [u, x] : V[v]) {
ll nd = d;
nd *= x;
if(nd <= P[u] && nd < dist[u]) {
dist[u] = nd;
Q.emplace(-nd, u);
}
}
}
return false;
}
void st() {
int n, m;
cin >> n >> m;
vi P(n);
cin >> P;
vector<vpii> V(n), V2(n);
FOR(i,0,m){
int a, b, c;
cin >> a >> b >> c;
a--; b--;
V2[a].EB(b, c);
V[b].EB(a, c);
}
if(!is_solvable(P, V2)) {
cout << -1 << endl;
return;
}
int ans = -1;
priority_queue<tuple<int, int, int, int>> Q;
Q.emplace(P.back(), P.back(),1, n - 1);
vector<set<pii>> seen(n);
seen.back().emplace(P.back(), 1);
while(!Q.empty()) {
auto [tp, p, mul, v] = Q.top();
Q.pop();
if(tp <= ans) continue;
if(v == 0) ans = max(ans, mul);
for (auto& [u, x] : V[v]) {
if(x <= p) {
int np = min(p / x, P[u]);
int nm = mul * x;
if (!seen[u].count(make_pair(np, nm))) {
int ntp = np * nm;
seen[u].emplace(np, nm);
Q.emplace(ntp, np, nm, u);
}
}
}
}
cout << ans << endl;
}
int main () {
ios_base::sync_with_stdio(false);
cin.tie(0);
int t;
cin >> t;
FOR(i,0,t){
//cout << "Case #" << i + 1 <<": ";
st();
}
}
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 | #include<bits/stdc++.h> #define FOR(i,a,b) for(int i=a;i<(int)b;++i) #define FORD(i,a,b) for(int i=a;i>=b;--i) #define PB push_back #define EB emplace_back #define FI first #define SE second #define umap unordered_map #define uset unordered_set #define vi vector<int> #define vvi vector<vi> #define vll vector<ll> #define vvll vector<vll> #define vpii vector<pii> #define pii pair<int, int> #define pll pair<ll, ll> #define ALL(X) (X).begin(),(X).end() #ifndef DEBUG #define endl (char)10 #endif using namespace std; using ll = long long; using ld = long double; template <class T> istream& operator>> (istream& is, vector<T>& vec){ FOR(i,0,vec.size()) is >> vec[i]; return is; } template <class T> ostream& operator<< (ostream& os, vector<T>& vec){ for(auto& t : vec) os << t << " "; return os; } template<class T, class U> ostream& operator<< (ostream& os, const pair<T, U>& p){ os << p.FI << " " << p.SE; return os; } template<class T, class U> istream& operator>> (istream& is, pair<T, U>& p){ is >> p.FI >> p.SE; return is; } bool is_solvable(vi& P, vector<vpii>& V) { priority_queue<pair<int, int>> Q; Q.emplace(-1, 0); vi dist(V.size(), INT_MAX); dist[0] = 1; while(!Q.empty()) { auto [d, v] = Q.top(); Q.pop(); d *= -1; if(d != dist[v]) continue; if (v == P.size() - 1) return true; for(auto& [u, x] : V[v]) { ll nd = d; nd *= x; if(nd <= P[u] && nd < dist[u]) { dist[u] = nd; Q.emplace(-nd, u); } } } return false; } void st() { int n, m; cin >> n >> m; vi P(n); cin >> P; vector<vpii> V(n), V2(n); FOR(i,0,m){ int a, b, c; cin >> a >> b >> c; a--; b--; V2[a].EB(b, c); V[b].EB(a, c); } if(!is_solvable(P, V2)) { cout << -1 << endl; return; } int ans = -1; priority_queue<tuple<int, int, int, int>> Q; Q.emplace(P.back(), P.back(),1, n - 1); vector<set<pii>> seen(n); seen.back().emplace(P.back(), 1); while(!Q.empty()) { auto [tp, p, mul, v] = Q.top(); Q.pop(); if(tp <= ans) continue; if(v == 0) ans = max(ans, mul); for (auto& [u, x] : V[v]) { if(x <= p) { int np = min(p / x, P[u]); int nm = mul * x; if (!seen[u].count(make_pair(np, nm))) { int ntp = np * nm; seen[u].emplace(np, nm); Q.emplace(ntp, np, nm, u); } } } } cout << ans << endl; } int main () { ios_base::sync_with_stdio(false); cin.tie(0); int t; cin >> t; FOR(i,0,t){ //cout << "Case #" << i + 1 <<": "; st(); } } |
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