#include <bits/stdc++.h>
using namespace std;
#define fwd(i, a, n) for (int i = (a); i < (n); i++)
#define rep(i, n) fwd(i, 0, n)
#define all(X) X.begin(), X.end()
#define sz(X) int(size(X))
#define pb push_back
#define eb emplace_back
#define st first
#define nd second
using pii = pair<int, int>; using vi = vector<int>;
using ll = long long; using ld = long double;
#ifdef LOC
auto SS = signal(6, [](int) { *(int *)0 = 0; });
#define DTP(x, y) auto operator << (auto &o, auto a) -> decltype(y, o) { o << "("; x; return o << ")"; }
DTP(o << a.st << ", " << a.nd, a.nd);
DTP(for (auto i : a) o << i << ", ", all(a));
void dump(auto... x) { (( cerr << x << ", " ), ...) <<
'\n'; }
#define deb(x...) cerr << setw(4) << __LINE__ << ":[" #x "]: ", dump(x)
#else
#define deb(...) 0
#endif
const int K = 40000;
const int N = 1e9;
const int M = ((N + K -1) / K) + 10;
void solve(){
int n, m; cin >> n >> m;
vector<int> p(n);
rep(i, n)cin >> p[i];
vector<vector<pii>> g(n);
vector<vector<pii>> revG(n);
rep(i, m){
int a, b, w; cin >> a >> b >> w;
a--; b--;
g[a].push_back({b, w});
revG[b].push_back({a, w});
}
vector<array<bool, K+1>> reach(n);
rep(i, n)rep(j, K+1)reach[i][j] = 0;
reach[0][1] = 1;
queue<pii> q;
q.push({0, 1});
while(!q.empty()){
auto [v, d] = q.front(); q.pop();
for(auto [u, w] : g[v]){
if(1ll * d * w <= p[u] && d * w <= K && !reach[u][d * w]){
reach[u][d*w] = 1;
q.push({u, d*w});
}
}
}
// deb(reach);
vector<array<int, M+1>> maxPow(n);
rep(i, n)rep(j, M+1)maxPow[i][j] = 0;
maxPow[n-1][1] = p[n-1];
priority_queue<array<int, 3>> pq;
pq.push({p[n-1], n-1, 1});
while(!pq.empty()){
auto [mp, v, mul] = pq.top(); pq.pop();
if(maxPow[v][mul] == mp){
for(auto [u, w] : revG[v]){
int d = min(p[u], mp / w);
if(1ll * mul * w <= M && maxPow[u][mul * w] < d){
maxPow[u][mul * w] = d;
pq.push({d, u, mul * w});
}
}
}
}
rep(i, n){
for(int j = M-1; j >= 0; j--){
maxPow[i][j] = max(maxPow[i][j], maxPow[i][j+1]);
}
}
// deb(maxPow);
int res = -1;
if(n == 1)res = 1;
rep(v, n){
for(auto [u, w] : g[v]){
int j = M;
for(int i = 1; i <= K; i++){
if(!reach[v][i])continue;
while(j > 0 && maxPow[u][j] < 1ll * i * w)j--;
if(j == 0)break;
res = max(res, i * w * j);
}
}
}
cout << res << "\n";
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout << fixed << setprecision(10);
int t; cin >> t;
while(t--)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 | #include <bits/stdc++.h> using namespace std; #define fwd(i, a, n) for (int i = (a); i < (n); i++) #define rep(i, n) fwd(i, 0, n) #define all(X) X.begin(), X.end() #define sz(X) int(size(X)) #define pb push_back #define eb emplace_back #define st first #define nd second using pii = pair<int, int>; using vi = vector<int>; using ll = long long; using ld = long double; #ifdef LOC auto SS = signal(6, [](int) { *(int *)0 = 0; }); #define DTP(x, y) auto operator << (auto &o, auto a) -> decltype(y, o) { o << "("; x; return o << ")"; } DTP(o << a.st << ", " << a.nd, a.nd); DTP(for (auto i : a) o << i << ", ", all(a)); void dump(auto... x) { (( cerr << x << ", " ), ...) << '\n'; } #define deb(x...) cerr << setw(4) << __LINE__ << ":[" #x "]: ", dump(x) #else #define deb(...) 0 #endif const int K = 40000; const int N = 1e9; const int M = ((N + K -1) / K) + 10; void solve(){ int n, m; cin >> n >> m; vector<int> p(n); rep(i, n)cin >> p[i]; vector<vector<pii>> g(n); vector<vector<pii>> revG(n); rep(i, m){ int a, b, w; cin >> a >> b >> w; a--; b--; g[a].push_back({b, w}); revG[b].push_back({a, w}); } vector<array<bool, K+1>> reach(n); rep(i, n)rep(j, K+1)reach[i][j] = 0; reach[0][1] = 1; queue<pii> q; q.push({0, 1}); while(!q.empty()){ auto [v, d] = q.front(); q.pop(); for(auto [u, w] : g[v]){ if(1ll * d * w <= p[u] && d * w <= K && !reach[u][d * w]){ reach[u][d*w] = 1; q.push({u, d*w}); } } } // deb(reach); vector<array<int, M+1>> maxPow(n); rep(i, n)rep(j, M+1)maxPow[i][j] = 0; maxPow[n-1][1] = p[n-1]; priority_queue<array<int, 3>> pq; pq.push({p[n-1], n-1, 1}); while(!pq.empty()){ auto [mp, v, mul] = pq.top(); pq.pop(); if(maxPow[v][mul] == mp){ for(auto [u, w] : revG[v]){ int d = min(p[u], mp / w); if(1ll * mul * w <= M && maxPow[u][mul * w] < d){ maxPow[u][mul * w] = d; pq.push({d, u, mul * w}); } } } } rep(i, n){ for(int j = M-1; j >= 0; j--){ maxPow[i][j] = max(maxPow[i][j], maxPow[i][j+1]); } } // deb(maxPow); int res = -1; if(n == 1)res = 1; rep(v, n){ for(auto [u, w] : g[v]){ int j = M; for(int i = 1; i <= K; i++){ if(!reach[v][i])continue; while(j > 0 && maxPow[u][j] < 1ll * i * w)j--; if(j == 0)break; res = max(res, i * w * j); } } } cout << res << "\n"; } int main(){ ios_base::sync_with_stdio(0); cin.tie(0); cout << fixed << setprecision(10); int t; cin >> t; while(t--)solve(); return 0; } |
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