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 <iostream>
#include <vector>
#include <climits>
#include <queue>

using namespace std;

const int kSize = 100001;

vector<int> V;

struct Node {
    int to;
    int weight;

    Node(int _to, int _weight) {
        to = _to;
        weight = _weight;
    }
};

int n;
vector<Node> adj[kSize];
bool isMarked[kSize];
int tree[kSize];
int dis[kSize];

void Dijkstra(int s) {
    dis[s] = 0;
    priority_queue<pair<int, int>, vector<pair<int, int> >, greater<> > pq;

    pq.push(make_pair(s, 0));
    //isMarked[s] = true;
    tree[s] = s;

    while (!pq.empty()) {
        pair<int, int> p = pq.top();
        pq.pop();
        int from = p.first;
        for (int i = 0; i < adj[from].size(); ++i) {
            int to = adj[from][i].to;
            if (dis[from] + adj[from][i].weight < dis[to]) {
                dis[to] = dis[from] + adj[from][i].weight;
                tree[to] = from;
                pq.push(make_pair(to, dis[to]));
            }
        }
    }

}

int main() {
    fill(isMarked, isMarked + kSize, false);
    fill(dis, dis + kSize, INT_MAX);
    cin >> n;
    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].emplace_back(v, c);
        }
    }

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

C++: #include<bits/stdc++.h>
using namespace std;
static const int INF=1000000;

int n;
vector<pair<int,int> > nex[10000];

void dijkstra(){ 
  priority_queue<pair<int,int> >PQ;
  int d[10000];
  int color[10000];  
  for(int i=0;i<n;i++){
    d[i]=INF;
    color[i]=0;
  }
  
  color[0]=1;
  d[0]=0;
  PQ.push(make_pair(0, 0));
  
  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<nex[u].size();j++){
      int v=nex[u][j].first;
      if(color[v] == 2) continue;
      if(d[v]>d[u]+nex[u][j].second){
        d[v]=d[u]+nex[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] == INF ?:d[i])<<endl;
  }
}


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

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

using namespace std;

const int MAXN = 10000;
const int INF = numeric_limits<int>::max();

vector< pair<int, int> > G[MAXN];
int dist[MAXN];
int n;

void dijkstra(int start) {
  for (int i = 0; i < n; ++i) dist[i] = INF;

  priority_queue< pair<int, int>, vector< pair<int, int> >, greater< pair<int, int> > > q;
  q.emplace(0, start);
  dist[start] = 0;
  while (!q.empty()) {
    pair<int, int> cur = q.top(); q.pop();
    int v = cur.second;
    int cost = cur.first;
    if (dist[v] < cost) continue;

    for (size_t i = 0; i < G[v].size(); ++i) {
      int u = G[v][i].first;
      int new_cost = G[v][i].second + cost;
      if (dist[u] > new_cost) {
	q.emplace(new_cost, u);
	dist[u] = new_cost;
      }
    }
  }
}
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, c;
      cin >> v >> c;
      G[u].emplace_back(v, c);
    }
  }
  dijkstra(0);
  for (int i = 0; i < n; ++i) {
    cout << i << " " << dist[i] << endl;
  }
  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
struct edge{
  int to,cost;
};
typedef pair<int,int> P;
int V;
vector<edge> G[100000];
int d[100000];
void dijkstra(int s){
  priority_queue<P ,vector<P>,greater<P> >que;
  fill(d,d+V,1e9+1);
  d[s]=0;
  que.push(P(0,s));
  //
  while(!que.empty()){
    P p=que.top();
    que.pop();
    int v=p.second;
    if(d[v]<p.first)continue;

    for(int i=0;i<G[v].size();i++){
      edge e=G[v][i];
      if(d[e.to]>d[v]+e.cost){
        d[e.to]=d[v]+e.cost;
        que.push(P(d[e.to],e.to));
      }
    }
  }
}
int main(){
  int k,u,v,c;
  cin >> V;
  for(int i=0;i<V;i++){
    cin >> u >> k;
    for(int j=0;j<k;j++){
      cin >> v >> c;
      edge ed;
      ed.to=v;
      ed.cost=c;
      G[u].push_back(ed);
    }
  }
  dijkstra(0);
  for(int i=0;i<V;i++){
    cout << i << " " << d[i] << endl;
  }
  return 0;
}