HackerRank "Dijkstra: Shortest Reach 2"

No big difference with "Breadth First Search: Shortest Reach", but this statement is crucial:

If there are edges between the same pair of nodes with different weights, they are to be considered as is, like multiple edges.

#include <cmath>
#include <cstdio>
#include <vector>
#include <string>
#include <iostream>
#include <algorithm>
#include <queue>
#include <unordered_map>
#include <unordered_set>
using namespace std;

typedef pair<int, long> Node; // index - dist
const long DIST_MAX = std::numeric_limits<long>::max();

vector<long> dist;
struct Comp
{
    int operator() (const Node &n1, const Node &n2)
    {
        return n1.second > n2.second;
    }
};
int main() 
{
    int t; cin >> t;
    while (t--)
    {
        unordered_map<int, unordered_map<int, int>> g;

        int n, m; cin >> n >> m;
        int mm = m;
        while (mm--){
            int x, y, r;
            cin >> x >> y >> r;
            x--, y--;
            if (g[x].find(y) == g[x].end())
                g[x][y] = r;
            else
                g[x][y] = std::min(g[x][y], r);
            if (g[y].find(x) == g[y].end())
                g[y][x] = r;
            else
                g[y][x] = std::min(g[y][x], r);
        }
        int s; cin >> s; s--;
        
        //
        dist.assign(n, DIST_MAX);
        dist[s] = 0;

        // inx
        priority_queue<Node, vector<Node>, Comp> hp;
        hp.push(Node(s, dist[s]));
        while (!hp.empty())
        {
            Node n = hp.top(); hp.pop();
            for (auto &c : g[n.first])
            {
                int j = c.first;
                int d = c.second;
                if (dist[j] == DIST_MAX || (dist[n.first] + d) < dist[j])
                {
                    dist[j] = dist[n.first] + d;
                    hp.push(Node(j, dist[j]));
                }
            }
        }

        //    output
        for (int i = 0; i < n; i++)
            if (i != s)
                cout << (dist[i] == DIST_MAX ? -1 : dist[i]) << " ";
        cout << endl;
    }
    return 0;
}

View Code