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;
using ll = long long;

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<endl
#define p2(s, t) cout << (s) << " " << (t) << endl
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << endl
#define p_yes() p("Yes")
#define p_no() p("No")

const ll mod = 1e9 + 7;
const ll inf = 1e18;

template < typename T >
void vprint(T &V){
	for(auto v : V){
    	cout << v << " ";
	}
	cout << endl;
}

struct Edge{
    ll to;
    ll cost;
    Edge(ll to, ll cost): to(to), cost(cost) {}
    Edge(){
        to = 0;
        cost = 0;
    }
};

struct Node{
    ll distance;
    ll index;
    Node(ll d, ll i){
        distance = d;
        index = i;
    }
    Node(){}

    bool operator<(const Node &another) const
    {
        return distance < another.distance;
    }
    bool operator>(const Node &another) const
    {
        return distance > another.distance;
    }
};

struct Dijkstra{
    vector<ll> d;
    vector<vector<Edge> > graph;
    vector<bool> done;

    // ノード数を入れる
    void initialize(ll size){
        d.resize(size);
        done.resize(size);
        graph.resize(size);
        reset();
    }

    void reset(){
        ll N = graph.size();
        FOR(i, 0, N){
            d[i] = inf;
            done[i] = false;
        }
    }
    
    ll distance(int i){
        if(d.size()<=i) return -1;
        return d[i];
    }

    void print_graph(){
        FOR(i, 0, graph.size()){
            cout << i << " -> ";

            for(auto edge : graph[i]){
                cout << edge.to << " ";
            }
            cout << endl;
        }
        p("distance");
        FOR(i, 0, graph.size()){
            ll d = distance(i);
            cout << i << " " << d << endl;
        }
    }

    void register_edge(ll a, ll b, ll cost){
        auto edge = Edge(b, cost);
        graph[a].push_back(edge);
    }

    void calc_shortest_path(ll from=0){
        priority_queue<Node, vector<Node>, greater<Node> > que;
        auto node = Node();
        // 始点
        node.index = from;
        node.distance = 0;
        que.push(node);

        while(!que.empty()){
            // 1番distanceが小さいノード
            Node n = que.top();
            que.pop();

            if(done[n.index]){
                continue;
            }
            
            done[n.index] = true;
            d[n.index] = n.distance;

            auto edge_list = graph[n.index];
            for(auto edge : edge_list){   
                // 短くなるノードがあれば
                if(!done[edge.to] && n.distance + edge.cost < d[edge.to]){
                    ll shorter_distance = n.distance + edge.cost;
                    que.push(Node(shorter_distance, edge.to));
                }
            }
        }
    }
};

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

    // input
    ll N;
    cin >> N;

    auto dij = Dijkstra();
    dij.initialize(N);

    FOR(i, 0, N){
        ll hoge; cin >> hoge;
        ll k; cin >> k;
        FOR(j, 0, k){
            ll v, c;
            cin >> v >> c;
            dij.register_edge(i, v, c);
        }
    }

    dij.calc_shortest_path();
    FOR(i, 0, N){
        ll d = dij.distance(i);
        p2(i, d);
    }
    
    return 0;
}

C++: #include<iostream>
#include<cstdio>
#define INF 1<<30
#define FinishFunction return 0
#define MAX 1000000
using namespace std;
 
 
struct edge {
  int from,to,cost,k;
};
 
edge es[MAX];
 
 
 
int main(){
  int n,u,k,E,c,v;
  E = 0;
  scanf("%d",&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);
      es[E].from = u;
      es[E].to = v;
      es[E++].cost = c;
    }
  }
 
   
  int d[MAX];
  for(int i=0;i<n;i++)d[i] = INF;
  d[0] = 0;
  while(true){
    bool update = false;
    for(int i=0;i<E;i++){
      edge e = es[i];
      if(d[e.from] != INF && d[e.to] > d[e.from] + e.cost){
    d[e.to] = d[e.from] + e.cost;
    update = true;
      }
    }
    if(!update)break;
 
 
  }
 
  for(int i=0;i<n;i++)cout << i << " " << d[i] << endl;
 
  FinishFunction;
}

C++: #include <iostream>
#include<algorithm>
#include<queue>
using namespace std;
static const int MAX = 10000;
static const int INFTY = (1<<20);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<pair<int, int> > adj[MAX];

void dijkstra(){
    priority_queue<pair<int, int> > PQ;
    int d[MAX],color[MAX];
    for(int i=0; i<n; i++){
        d[i]=INFTY;
        color[i]=WHITE;
    }
    
    d[0]=0;
    PQ.push(make_pair(0, 0));
    color[0]=GRAY;

    
    while (!PQ.empty()) {
        pair<int, int> f = PQ.top(); PQ.pop();
        int u = f.second;
        color[u] = BLACK;
        // 最小値を取り出し、それが最短でなければ無視
        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]==BLACK) 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]=GRAY;
            }
            }
        }
    
    
    for(int i=0; i<n; i++){
      cout << i << " "<< ( d[i] == INFTY ? -1 : d[i] ) << endl;
    }
}



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