Baekjoon #14284

#include<bits/stdc++.h>

using namespace std;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int N, M; cin >> N >> M;
    vector<vector<pair<int, int>>> G(N + 1);
    for(int i = 0; i < M; ++i) {
        int u, v, w; cin >> u >> v >> w;
        G[u].emplace_back(v, w);
        G[v].emplace_back(u, w);
    }
    int S, T; cin >> S >> T;

    priority_queue<pair<int, int>> pq;
    const int INF = 0x3f3f3f3f;
    vector<int> dist(N + 1, INF);
    dist[S] = 0;
    pq.emplace(0, S);
    while(!pq.empty()) {
        auto [d, cur] = pq.top(); pq.pop();
        if(dist[cur] != -d) continue;
        for(auto [nxt, w]: G[cur]) {
            if(dist[nxt] > dist[cur] + w) {
                dist[nxt] = dist[cur] + w;
                pq.emplace(-dist[nxt], nxt);
            }
        }
    }
    cout << dist[T];

    return 0;
}

import java.util.*;
import java.io.*;

public class Main {
    public static void main(String[] args) {
        FastReader rd = new FastReader();
        int N = rd.nextInt();
        int M = rd.nextInt();

        List<int[]> list[] = new ArrayList[N + 1];
        for (int i = 1; i <= N; i++) {
            list[i] = new ArrayList<>();
        }

        for (int i = 0; i < M; i++) {
            int a = rd.nextInt();
            int b = rd.nextInt();
            int c = rd.nextInt();

            list[a].add(new int[]{b, c});
            list[b].add(new int[]{a, c});
        }

        int st = rd.nextInt();
        int ed = rd.nextInt();

        PriorityQueue<int[]> pq = new PriorityQueue<>((n1, n2) -> n1[1] - n2[1]);
        int[] dist = new int[N + 1];
        int INF = (int) 1e9;
        Arrays.fill(dist, INF);
        pq.add(new int[]{st, 0});
        dist[st] = 0;

        while (!pq.isEmpty()) {
            int[] curr = pq.poll();

            if (curr[0] == ed) break;

            for (int[] next : list[curr[0]]) {
                if (dist[next[0]] > curr[1] + next[1]) {
                    dist[next[0]] = curr[1] + next[1];
                    pq.add(new int[]{next[0], dist[next[0]]});
                }
            }
        }

        System.out.println(dist[ed]);
    }

    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }
}