Go: package main

import (
	"fmt"
	"bufio"
	"os"
	"strconv"
	"container/heap"
)

type Node struct {
	Id int
	Dis int
}

type PriorityQueue []*Node

func (pq PriorityQueue) Len() int { return len(pq) }

func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].Dis < pq[j].Dis
}

func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
}

func (pq *PriorityQueue) Push(x interface{}) {
	*pq = append(*pq, x.(*Node))
}

func (pq *PriorityQueue) Pop() interface{} {
	n := len(*pq)
	pop := (*pq)[n-1]
	*pq = (*pq)[0:n-1]
	return pop
}

func main() {
	var n int
	fmt.Scan(&n)

	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	g := make([][]int, n)
	c := make([][]int, n)
	pq := make(PriorityQueue, 0, n)
	d := make([]int, n)
	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())
		g[u] = make([]int, k)
		c[u] = make([]int, k)
		for j := 0; j < k; j++ {
			sc.Scan()
			g[u][j], _ = strconv.Atoi(sc.Text())
			sc.Scan()
			c[u][j], _ = strconv.Atoi(sc.Text())
		}

		if u == 0 {
			d[u] = 0
		} else {
			d[u] = 1 << 30
		}
		pq.Push(&Node{u, d[u]})
	}
	heap.Init(&pq)

	for pq.Len() > 0 {
		node := heap.Pop(&pq).(*Node)
		for i := 0; i < len(g[node.Id]); i++ {
			nextId := g[node.Id][i]
			nextDis := node.Dis + c[node.Id][i]
			if nextDis < d[nextId] {
				d[nextId] = nextDis
				heap.Push(&pq, &Node{nextId, nextDis})
			}
		}
	}

	wr := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		wr.WriteString(strconv.Itoa(i))
		wr.WriteString(" ")
		wr.WriteString(strconv.Itoa(d[i]))
		wr.WriteString("\n")
	}
	wr.Flush()
}

C++: #include <bits/stdc++.h>
using namespace std;

#define INF 2000000000
#define WH 0
#define GR 1
#define BK 2

int main() {
    int n;
    cin >> n;
    vector<pair<int, int>> adj[10000];
    for (int i = 0; i < n; i++) {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            int v, c;
            cin >> v >> c;
            adj[u].push_back(make_pair(v, c));
        }
    }

    int color[10000] = {};
    int d[10000];
    for (int i = 0; i < n; i++) {
        d[i] = INF;
    }

    int p[10000];
    for (int i = 0; i < n; i++) {
        p[i] = -1;
    }

    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> PQ;  // (cost, unit)


    d[0] = 0;
    PQ.push(make_pair(0, 0));

    while (PQ.empty() == false) {
        pair<int, int> q = PQ.top(); PQ.pop();
        int u = q.second;

        if (d[u] < q.first) {
            continue;
        }

        color[u] = BK;

        for (int j = 0; j < adj[u].size(); j++) {
            int v = adj[u][j].first;
            int c = adj[u][j].second;
            if (color[v] != BK) {
                if (d[u] + c < d[v]) {
                    d[v] = d[u] + c;
                    PQ.push(make_pair(d[v], v));
                    p[v] = u;
                }
            }
        }
    }

    for (int i = 0; i < n; i++) {
        cout << i << " " << d[i] << endl;
    }

    return 0;

}

C++: #include <iostream>
#include <vector>
#include <queue>

using ll = long long;
using namespace std;
/* initialize */
int n;
vector<pair<int, int> > adj[10000];

void dijkstra(){
    priority_queue<pair<int,int> > PQ;
    int color[10000];
    int d[10000];
    for (int i = 0; i < n; ++i) {d[i] = INT32_MAX; color[i] = 0;};
    d[0] = 0;
    PQ.push(make_pair(0, 0));
    color[0] = 1;
    while (!PQ.empty()){
        pair<int, int> f = PQ.top(); PQ.pop();
        int u = f.second;
        color[u] = 2;
        if (d[u] < f.first * (-1)) continue;

        for (int j = 0; j < adj[u].size(); ++j) {
            int v = adj[u][j].first;
            if(color[v] == 2) continue;
            if (d[v] > d[u] + adj[u][j].second){
                d[v] = d[u] + adj[u][j].second;
                PQ.push(make_pair(d[v]*-1, v));
                color[v] = 1;
            }
        }
    }
    for (int i = 0; i < n; ++i) {
        cout << i << " " << (d[i] == INT32_MAX ? -1 : d[i]) << "\n";
    }
};
/* main */
int main() {
    int k, u, v, c;

    cin >> n;
    for (int i = 0; i < n; ++i) {
        scanf("%d %d", &u, &k);
        for (int j = 0; j < k; ++j) {
            scanf("%d %d", &v, &c);
            adj[u].emplace_back(v,c);
        }
    }
    dijkstra();
    return 0;
}

C++: #include <stdio.h>
#include <vector>
#include <queue>

using namespace std;
#define MAX_N (10010)
#define INF (1000000100)
typedef struct {
    int to;
    int w;
} Edge;

vector<Edge> G[MAX_N];
int n;

int dist[MAX_N];
bool arrived[MAX_N];

void dijkstra(int s)
{
    priority_queue< pair<int, int> > PQ;
    for ( int i = 0; i < n; i++ ) {
	dist[i] = INF;
	arrived[i] = false;
    }

    dist[s] = 0;
    PQ.push(make_pair(0, 0));

    while ( !PQ.empty() ) {
	pair<int, int> u = PQ.top(); PQ.pop();
	if ( u.second > dist[u.first] ) continue;
	arrived[u.first] = true;
	
	for ( int i = 0; i < G[u.first].size(); i++ ) {
	    Edge e = G[u.first][i];
	    if ( !arrived[e.to] && dist[e.to] > (dist[u.first] + e.w) ) {
		dist[e.to] = dist[u.first] + e.w;
		PQ.push(make_pair(e.to, dist[e.to]));
	    }
	}
    }

}

int main()
{
    scanf("%d", &n);
    
    for ( int i = 0; i < n; i++ ) {
	int u, k;
	scanf("%d %d", &u, &k);

	for ( int j = 0; j < k; j++ ) {
	    int v, c;
	    Edge e;
	    scanf("%d %d", &v, &c);
	    e.to = v;
	    e.w = c;
	    G[u].push_back(e);
	}
    }

    dijkstra(0);

    for ( int i = 0; i < n; i++ ) {
	printf("%d %d\n", i, dist[i]);
    }

    return 0;
}

C++: #include <iostream>
#include <vector>
#include <queue>

#define INF 1000000000
using namespace std;

struct edge {
    int from;
    int to;
    int w;
};
struct node {
    node() : id {-1}, d {INF}, ns {} {};
    node(int i, vector<edge>& vec) : id {i}, d {INF}, ns {vec} {};
    int id;
    int d;
    vector<edge> ns;
};

struct node_s {
    int id;
    int d;
};

vector<int> dijkstra(node* graph, int n, int st){
    auto ds = vector<int>(n, INF);
    auto comp = [](node_s* x, node_s* y){return x->d > y->d;};
    priority_queue<node_s*, vector<node_s*>, decltype(comp)> que(comp);
    node_s* start = new node_s {graph[st].id, 0};
    que.push(start);
    while(que.size()){
        node_s* n = que.top();
    /    cout << n->id << ' ' << n->d << endl;
        que.pop();
        if(n->d < ds[n->id]){
            ds[n->id] = n->d;
            for(auto e : graph[n->id].ns){
                if(ds[e.to] < INF){
                    continue;
                }
                node_s* next_n = new node_s {graph[e.to].id, ds[n->id] + e.w};
                que.push(next_n);
            }
        }
        delete n;
    }
    return ds;
}

int main(){
    cin.sync_with_stdio(false);
    cout.sync_with_stdio(false);
    int n;
    cin >> n;
    node graph[n];
    for(int i = 0; i < n; ++i){
        int id;
        int m;
        cin >> id >> m;
        auto vec = vector<edge>(m);
        int v, c;
        for(int j = 0; j < m; ++j){
            cin >> v >> c;
            vec[j] = edge {id, v, c};
        }
        graph[id] = node(id, vec);
    }
    auto ds = dijkstra(graph, n, 0);
    for(int i = 0; i < n; ++i){
        cout << i << ' ' << ds[i] << endl;
    }
}