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 rep(i,n) for(int i=0;i<(n);i++)

const long long INFF = 1e18;

const int MAX_N = 11000;
using TYPE = long long; // ?????¢???????????\??????
vector<pair<int, TYPE> > G[MAX_N];

vector<TYPE> A_star(int start){
	vector<TYPE> dist(MAX_N, INFF);
	dist[start] = 0;//dist[i] :=???start->i?????§??????????????¢
	priority_queue<pair<TYPE, int>, vector<pair<TYPE, int> >, greater<pair<TYPE, int> > >  que;
	que.push(make_pair(0, start));
	while(!que.empty()){
		TYPE cost; int u;//????????§???????????£????????? ?????¨?????????
		cost = que.top().first, u = que.top().second;
		que.pop();
		// if(dist[u] < cost) continue;
		for (auto tmp : G[u]){
			int v = tmp.first; TYPE time = tmp.second;//??£??\???????????? ?????????????????§????????????
			if(dist[v] > dist[u] + time){//u->v
				dist[v] = dist[u] + time;
				auto h = 0; // ??´???????????§?????¨??????
				// printf("%f\n", h);
				que.push(make_pair(dist[v] + h, v));
			}
		}
	}
	return dist;
}

int main(void) {
	int n; cin >> n;
	rep(q, n) {
		int u, k; cin >> u >> k;
		vector<int> v(k), c(k);
		rep(i, k) cin >> v[i] >> c[i];
		rep(i, k) G[u].push_back(make_pair(v[i], c[i])), G[v[i]].push_back(make_pair(u, c[i]));
	}
	auto dist = A_star(0);
	rep(i, n) printf("%d %d\n", i, dist[i]);
	return 0;
}

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

    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;

        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;
}

C++: #include <iostream>
#include<queue>
using namespace std;
const int MAXn=10000;
const int INFTY=1<<21;

int n,col[MAXn],d[MAXn];
vector<pair<int,int>> Q[MAXn];

void dijkstra(int s)
{
	priority_queue<pair<int,int>> PQ;//weight,id
	for(int i=0;i<n;i++)
	{
		d[i]=INFTY;
		col[i]=0;
	}
	d[s]=0;
	PQ.push(make_pair(0,s));
	col[s]=1;
	
	while(!PQ.empty())
	{
		pair<int,int> f=PQ.top();PQ.pop();
		int u=f.second;
		col[u]=2;
		if(d[u]<f.first*(-1))continue;
		for(int j=0;j<Q[u].size();j++)
		{
			int v=Q[u][j].first;
			if(col[v]==2)continue;
			if(d[u]+Q[u][j].second<d[v])
			{
				d[v]=d[u]+Q[u][j].second;
				PQ.push(make_pair(d[v]*(-1),v));
				col[v]=1;
			}
		}
	}
	
	for(int i=0;i<n;i++)cout<<i<<" "<<(d[i]==INFTY?-1:d[i])<<endl;
	
	return;
}

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

C++: #include<iostream>
#include<algorithm>
#include<cstring>
#include<queue>
#include<vector>
#define WHITE 0
#define BLACK 1
#define GRAY 2
using namespace std;
const int MAXN = 10000 + 4;
const int INF = 0x3f3f3f3f;
int status[MAXN], d[MAXN];
int N;
vector< pair<int, int> > ADJ[MAXN];
void Dijkstra (  )
{
    priority_queue< pair<int, int> > PQ;
    memset( status, WHITE, sizeof(status) );
    for ( int i = 0; i < N; i++ ) d[i] = INF;
    d[0] = 0;
    status[0] = GRAY;
    PQ.push(make_pair(0, 0));

    while ( !PQ.empty() ) {
        pair<int, int> f = PQ.top(); PQ.pop();
        int u = f.second;
        status[u] = BLACK;

        if ( d[u] < f.first * (-1) ) continue;

        for ( int j = 0; j < ADJ[u].size(); j++ ) {
            int v = ADJ[u][j].first;
            if ( status[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));
                status[v] = GRAY;
            }
        }
    }
    for ( int i = 0; i < N; i++ ) {
        cout<<i<<' '<<( d[i] == INF ? -1 : d[i] )<<endl;
    }
}

int main()
{
    int u, D, c, v;
    cin>>N;
    for ( int i = 0; i < N; i++ ) {
        cin>>u>>D;
        for ( int j = 0; j < D; j++ ) {
            cin>>v>>c;
            ADJ[u].push_back(make_pair(v, c));
        }
    }

    Dijkstra();
    return 0;
}

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 color[MAX];
  int d[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;

    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;
}