Go: package main

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

type Item struct {
	value    int // The value of the item; arbitrary.
	priority int // The priority of the item in the queue.
	// The index is needed by update and is maintained by the heap.Interface methods.
	index int // The index of the item in the heap.
}
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }
func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].priority < pq[j].priority
}
func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = i
	pq[j].index = j
}
func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}
func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	item.index = -1 // for safety
	*pq = old[0 : n-1]
	return item
}

type Q struct {
	pq *PriorityQueue
	ds map[int]int // It has always same value as pq. For random access.
}

func newQ() *Q {
	pq := new(PriorityQueue)
	heap.Init(pq)
	return &Q{
		pq: pq,
		ds: make(map[int]int),
	}
}
func (q *Q) pop() (u, d int) {
	item := heap.Pop(q.pq).(*Item)
	delete(q.ds, item.value)
	return item.value, item.priority
}
func (q *Q) get(u int) (int, bool) { // returns d
	d, ok := q.ds[u]
	return d, ok
}
func (q *Q) set(u, d int) {
	q.ds[u] = d
	for _, item := range *q.pq {
		if item.value != u {
			continue
		}

		item.priority = d
		heap.Fix(q.pq, item.index)
		return
	}
	heap.Push(q.pq, &Item{
		priority: d,
		value:    u,
	})
}
func (q *Q) len() int {
	return len(q.ds)
}

func main() {
	r := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(r, &n)
	cs := make([]map[int]int, n) // []v_i -> c_i
	for h := 0; h < n; h++ {
		var u, k int
		fmt.Fscan(r, &u, &k)
		m := make(map[int]int)
		for i := 0; i < k; i++ {
			var v, c int
			fmt.Fscan(r, &v, &c)
			m[v] = c
		}

		cs[u] = m
	}

	q := newQ()
	q.set(0, 0)
	visited := make(map[int]struct{})
	out := make([]int, n)

	for q.len() > 0 {
		u, d := q.pop()
		for uu, c := range cs[u] {
			// Consider the connection between u and uu.
			if _, ok := visited[uu]; ok {
				continue
			}
			dd := d + c
			if d, ok := q.get(uu); !ok || d > dd {
				q.set(uu, dd)
			}
		}

		out[u] = d
		visited[u] = struct{}{}
	}

	for u, d := range out {
		fmt.Println(u, d)
	}
}

C++: #include<stdio.h>
#include<vector>
#include<queue>
#include<map>
#include<algorithm>
#include<queue>
#include<functional>
using namespace std;
int main(){
	int s;
	int g;
	int a;
	int b;
	int f;
	int t;
	vector<int> n[10000];
	int nn[10000];
	vector<int> x[10000];
	priority_queue<pair<int, int>, vector<pair<int, int> >, greater<pair<int, int> > >y;
	vector<pair<int, int> >::iterator yy;
	int z;
	int d[10000];
	int e;
	int c[10000];
	int p;
	int q;
	int zz;
	pair<int, int>pai;
	for (int i = 0; i < 10000; i++){
		d[i] = 1000000009;
		c[i] = 0;
	}
	scanf("%d", &a);
	for (int i = 0; i < a; i++){
		scanf("%d %d", &s, &b);
		for (int j = 0; j < b; j++){
			scanf("%d %d",&t, &e);
			if (s > t){
				n[s].push_back(t);
				n[t].push_back(s);
				nn[s]++;
				nn[t]++;
				x[s].push_back(e);
				x[t].push_back(e);
			}
		}
	}
	d[0] = 0;
	y.push(std::make_pair(d[0], 0));
	for (int i = 0; y.empty() == 0; i++){
		zz = 0;
		for (int j = 0; y.empty() == 0 && zz == 0; j++){
			pai = y.top();
			z = pai.second;
			if (c[z] == 0)zz++;
			else y.pop();
		}
		if (zz == 0)break;
		c[z] = 1;
		for (int j = 0; j < nn[z]; j++){
			if (d[z] + x[z][j] < d[n[z][j]])
			{
				d[n[z][j]] = d[z] + x[z][j];
				y.push(std::make_pair(d[n[z][j]], n[z][j]));
			}
		}
		y.pop();
	}
	for (int i = 0; i < a; i++){
		printf("%d %d\n",i, d[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]=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;
}

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <stack>
#include <vector>
#include <algorithm>
#include <cmath>
#include <climits>
#include <cstring>
#include <queue>
#include <string>

using namespace std;

const double PI = 3.14159265358979;

//int G[101][101];
int visited[10001];
int n;

int d[10001];


struct Vertex {
	int u;
	int weight;

	friend bool operator < (Vertex a, Vertex b) {
		return a.weight > b.weight;
	}
};

vector<Vertex> G[10001];

void dijkstra(int start) {

	priority_queue<Vertex> PQ;

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

	d[start] = 0;
	PQ.push(Vertex{ 0,0 });

	while (!PQ.empty()) {
		Vertex f = PQ.top();
		PQ.pop();
		int u = f.u;
		if (visited[u]) {
			continue;
		}
		else {
			visited[u] = 1;
		}

		//if (f.weight > d[u]) continue;

		
		for (int j = 0; j < G[u].size(); j++)
		{
			int v = G[u][j].u;
			if (!visited[v]) {
				if (d[u] + G[u][j].weight < d[v]) {
					PQ.push(Vertex{ v, d[u] + G[u][j].weight });
					d[v] = d[u] + G[u][j].weight;
				}
			}
		}
	}


}

int main() {
	
	
	cin >> n;

	for (int i = 0; i < n; i++)	{
		int u, k; cin >> u >> k;
		for (int j = 0; j < k; j++)	{
			int v, w; cin >> v >> w;
			G[u].push_back(Vertex{ v, w });
		}
	}

	dijkstra(0);

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

	return 0;
}

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

#define MAX_NODE 10000
#define INF 1000000000

using namespace std;

struct Edge {
	int to, w;
};

typedef pair<int, int> P;

vector<Edge> adj[MAX_NODE];
int d[MAX_NODE];

void dijkstra(int n, int start) {
	priority_queue<P, vector<P>, greater<P> > heap;
	fill(d, d + n, INF);
	d[start] = 0;
	heap.push({0, start});

	while (!heap.empty()) {
 		P p = heap.top();
 		heap.pop();
 		int from = p.second;
 		if (d[from] < p.first)
 			continue;
 		for (int i = 0; i < adj[from].size(); i++) {
 			Edge e = adj[from][i];
	 		if (d[from] + e.w < d[e.to]) {
	 			d[e.to] = d[from] + e.w;
	 			heap.push( {d[e.to], e.to} );
	 		}
	 	}
	}
}

int main(){
	int n,u,k,c,v;
	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({v,c});
		}
	}
	dijkstra(n,0);
	for(int i=0;i<n;i++){
		cout<<i<<" "<<d[i]<<"\n";
	}
	return 0;
}