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<cmath>
#include<algorithm>
#include<stack>
#include<queue>
#include<vector>

typedef long long int ll;

#define BIG_NUM 2000000000

using namespace std;

struct Node {
    Node(int arg_to, int arg_cost) {
        to = arg_to;
        cost = arg_cost;
    }
    
    bool operator<(const struct Node &arg) const{
        return cost > arg.cost;
    };
    
    int to, cost;
};

int main() {
    int N;
    scanf("%d", &N);
    
    vector<Node> V[N];
    
    int node, num, to, cost, D[N];
    
    for(int loop = 0; loop < N; loop++) {
        scanf("%d", &node);
        scanf("%d", &num);
        
        for(int i = 0; i < num; i++) {
            scanf("%d %d", &to, &cost);
            V[node].push_back(Node(to, cost));
        }
        D[loop] = BIG_NUM;
    }
    
    D[0] = 0;
    
    priority_queue<Node> Q;
    
    for(int i = 0; i < V[0].size(); i++) {
        D[V[0][i].to] = V[0][i].cost;
        Q.push(Node(V[0][i].to, V[0][i].cost));
    }
    
    int min_index;
    
    while(!Q.empty()) {
        if(Q.top().cost == D[Q.top().to]) {
            min_index = Q.top().to;
            Q.pop();
        }else {
            Q.pop();
            continue;
        }
        
        for(int k = 0; k < V[min_index].size(); k++) {
            if(D[V[min_index][k].to] > D[min_index] + V[min_index][k].cost) {
                D[V[min_index][k].to] = D[min_index] + V[min_index][k].cost;
                Q.push(Node(V[min_index][k].to, D[V[min_index][k].to]));
            }
        }
    }
    
    for(int i = 0; i < N; i++) printf("%d %d\n", i, D[i]);
    
    return 0;
}

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

typedef pair<int, int> node;
typedef vector<node> Adj_list;
typedef vector<Adj_list> Adj_lists;

class less_cost{
public:
  bool operator()(const pair<int, int> lhs, const pair<int, int> rhs) const{
    return lhs.second < rhs.second;
  }
};

int main(){

  int n;
  scanf("%d", &n);

  Adj_lists adj_lists(n);

  // read weigts
  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;
      scanf("%d %d", &v, &c);
      adj_lists.at(u).push_back(node(v, c));
    }
  }

  // initialize cost
  vector<int> d(n, INT_MAX);
  d.at(0) = 0;
  priority_queue<node, vector<node>, less_cost> pq;
  pq.push(node(0, d.at(0)));
  vector<bool> is_belong_to_sssp(n, false);

  //dijkstra's algorithm
  while(!pq.empty()){
    // extract node u in V-S that has minimum cost
    const node u = pq.top();
    pq.pop();
    is_belong_to_sssp.at(u.first) = true;

    // if u's cost is larger than d[u],
    // than ignore this one
    if(u.second < d.at(u.first)) continue;

    // update node in V-S and adjacent to u
    for(const node& v : adj_lists.at(u.first)){
      if(!is_belong_to_sssp.at(v.first) && d.at(u.first) + v.second < d.at(v.first)){
        d.at(v.first) = d.at(u.first) + v.second;
        pq.push(node(v.first, d.at(v.first)));
      }
    }
  }

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

  return 0;
}

C++: #include <iostream>
#include <stdio.h>
#include <cstring>
#include <math.h>
#include <algorithm>
#include <vector>
#include <string>
#include <stdlib.h>
#include <queue>
#include <stack>
#include <utility>
#define rep(i,n) for(int i=0;i<n;i++)
#define rrep(i,n) for(int i=n-1;i>=0;i--)
#define FOR(i,a,b) for(int i=a;i<b;i++)
#define ll long long
#define INF 1000000001
#define mod 1000000007
using namespace std;

int main(){
	
	int n,aaa;
	cin>>n;
	vector<vector<int>> v(n),c(n);
	vector<int> k(n),ans(n),d(n);
	rep(i,n){
		cin>>aaa>>k[i];
		v[i].resize(k[i]);
		c[i].resize(k[i]);
		rep(j,k[i]){
			cin>>v[i][j]>>c[i][j];
		}
		ans[i]=-1;
		d[i]=INF;
	}
	d[0]=0;
	int m=INF,mi;
	rep(aaaa,n){
		m=INF;
		rep(i,n){
			if(ans[i]==-1 && d[i]<m){
				m=d[i];
				mi=i;
			}
		}
		ans[mi]=m;
		rep(j,k[mi]){
			d[v[mi][j]]=min(ans[mi]+c[mi][j],d[v[mi][j]]);
		}
	}



	rep(i,n){
		cout<<i<<" "<<ans[i]<<endl;
	}
	
}

C++: #include<iostream>
#include<algorithm>
#include<queue>
using namespace std;
static const int Max = 10000;
static const int Infty = (1<<20);
static const int W = 0;
static const int G = 1;
static const int B = 2;

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

void dijkstra(){
  priority_queue<pair<int, int> > PQ;
  int i, j, u, v, color[Max], d[Max];

  for(i = 0 ; i < n ; i++){
    d[i] = Infty;
    color[i] = W;
  }

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

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

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

    for(j = 0 ; j < adj[u].size() ; j++){
      v = adj[u][j].first;
      if(color[v] == B) 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] = G;
      }
    }
  }

  for(i = 0 ; i < n ; i++){
    cout << i << " " << (d[i] == Infty ? -1 : d[i]) << endl;
  }
}



int main(){
  int i, j, k, u, v, c;

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

  dijkstra();

  return 0;
}