BOJ 13308

#include <iostream>
#include <vector>
#include <queue>
#include <algorithm>
using namespace std;
#define MAXN 2501
#define INF 3e10
typedef long long ll;
struct node{
    int cur;
    int cur_w;
    ll cur_wl;
    bool operator < (const node& a) const{
        return a.cur_wl < cur_wl;
    }
};
int Won[MAXN];
vector<pair<int,int> > adj[MAXN];
ll dist[MAXN][MAXN];
int N,M;
ll dijkstra(){
    priority_queue<node> pq;
    pq.push({1,Won[1],0});
    dist[1][Won[1]] = 0;
    while (!pq.empty()){
        int cur = pq.top().cur;
        ll cur_wl = pq.top().cur_wl;
        int cur_w = pq.top().cur_w;
        pq.pop();
        if (cur == N) return cur_wl;
        for (int i = 0 ;i  < adj[cur].size(); i++){
            int next = adj[cur][i].first;
            int next_l = adj[cur][i].second;
            ll next_wl = cur_wl + (ll)cur_w*next_l;
            if (dist[next][min(cur_w,Won[next])] > next_wl){
                dist[next][min(cur_w,Won[next])] = next_wl;
                pq.push({next,min(cur_w,Won[next]),next_wl});
            }
        }
    }
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin >> N >> M;
    for (int i = 1; i <=N ; i++){
        cin >> Won[i];
    }
    while (M--){
        int u,v,l;
        cin >> u >> v >> l;
        adj[u].push_back({v,l});
        adj[v].push_back({u,l});
    }
    for (int i = 1; i <=N; i++){
        for (int j = 1; j<MAXN; j++){
            dist[i][j] = INF;
        }
    }
    cout << dijkstra() <<"\n";
    return 0;
}