Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
const INF = 1 << 60

type Edge struct {
	to, cost int
}

type Node struct {
	id, cost int
}

type PQ []Node

func (pq PQ) Len() int           { return len(pq) }
func (pq PQ) Less(i, j int) bool { return pq[i].cost < pq[j].cost }
func (pq PQ) Swap(i, j int)      { pq[i], pq[j] = pq[j], pq[i] }

func (pq *PQ) Push(x interface{}) {
	*pq = append(*pq, x.(Node))
}

func (pq *PQ) Pop() interface{} {
	old := *pq
	n := len(old)
	x := old[n-1]
	*pq = old[0 : n-1]
	return x
}

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	E := make([][]Edge, N)
	for i := 0; i < N; i++ {
		id, k := sc.nextInt(), sc.nextInt()
		E[id] = make([]Edge, k)
		for j := 0; j < k; j++ {
			to, cost := sc.nextInt(), sc.nextInt()
			E[id][j] = Edge{to, cost}
		}
	}

	d := make([]int, N)
	for i := 0; i < N; i++ {
		d[i] = INF
	}
	done := make([]bool, N)
	pq := &PQ{}
	heap.Init(pq)
	d[0] = 0
	heap.Push(pq, Node{0, 0})
	for pq.Len() > 0 {
		cur := heap.Pop(pq).(Node).id
		if done[cur] {
			continue
		}
		done[cur] = true
		for i := 0; i < len(E[cur]); i++ {
			to, cost := E[cur][i].to, E[cur][i].cost+d[cur]
			if !done[to] && cost < d[to] {
				d[to] = cost
				heap.Push(pq, Node{to, cost})
			}
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i, d[i])
	}
	wtr.Flush()
}

C++: // ALDS1_12_C: Single Source Shortest Path II
#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#include <utility>
#define NIL -1
#define INF 1000000
using intpair = std::pair<int,int>;
bool debug = false;

std::vector<std::vector<intpair>> adjacency_list; // pair = (vertex_num, weight)
std::vector<bool> node_stat;
std::vector<int> minimum_cost;
std::priority_queue<intpair, std::vector<intpair>, std::greater<intpair>> que; // pair = (weight, vetrex_num)

void dijkstra(int vertex) {
    if (debug) std::cout << "dijkstra(" << vertex << ")\n";
    // 1. mark as visited
    node_stat.at(vertex) = false;

    // 2. push weights into priority queue.
    for (int i=0; i<adjacency_list.at(vertex).size(); i++) {
        int next = adjacency_list.at(vertex).at(i).first;
        int edge_weight = adjacency_list.at(vertex).at(i).second;
        int weight = minimum_cost.at(vertex) + edge_weight;

        if (debug) std::cout << "next = " << next << ", weight = " << weight << "\n";
        intpair tmp = std::make_pair(weight, next);
        que.push(tmp);
    }

    // 3. get appropriate next_vertex and determine minimum_cost(next_vertex)
    int next = NIL;
    int size = que.size(); // do NOT use .size() when it can change!!!!!!
    for (int i=0; i<size; i++) {
        int cost = que.top().first, next_vertex = que.top().second;
        que.pop(); 
        if (node_stat.at(next_vertex)) {
            if (cost < minimum_cost.at(next_vertex)) {
                minimum_cost.at(next_vertex) = cost;
                next = next_vertex;
                break;
            }
        }
    }
    // 4. end of recursion
    if (next == NIL) return;

    // 5. recurving
    dijkstra(next);
}

int main() {
    int total_node_num; std::cin >> total_node_num;
    adjacency_list.resize(total_node_num);
    node_stat.assign(total_node_num, true);
    minimum_cost.assign(total_node_num, INF);
    minimum_cost.at(0) = 0;

    for (int i=0; i<total_node_num; i++) {
        int vertex, outdegree; std::cin >> vertex >> outdegree;
        for (int j=0; j<outdegree; j++) {
            std::pair<int,int> tmp; std::cin >> tmp.first >> tmp.second;
            adjacency_list.at(vertex).push_back(tmp);
        }
    }

    dijkstra(0);
    for (int i=0; i<minimum_cost.size(); i++) {
        std::cout << i << " " << minimum_cost.at(i) << "\n";
    }
}

C++: #include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX 100000
#define EMAX 500000
#define INFTY 2000000000
typedef struct {
  int pre,next,x;
}Cost;
int n,d[MAX];
Cost E[EMAX];
void jr(int);

void jr(int cou){
  int i,tmp;

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

  d[0]=0;

  tmp=1;
  while(tmp!=0){
    tmp=0;
    for(i=0;i<cou;i++){
      if(E[i].x+d[E[i].pre]<d[E[i].next]){
	d[E[i].next]=E[i].x+d[E[i].pre];
	tmp=1;
      }
    }
  }
}

int main()
{
  int n,i,j,u,k,v,cou=0;

  scanf("%d",&n);

  for(i=0;i<n;i++){
    scanf("%d %d",&u,&k);
    for(j=0;j<k;j++){
      E[cou].pre=u;
      scanf("%d %d",&E[cou].next,&E[cou].x);
      cou++;
    }
  }

  jr(cou);

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

  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define INF 1000000000
#define MAX 10000

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

void dijkstra(int start){
  priority_queue<pair<int,int>> pq;
  for(int i=0;i<n;i++){
    d[i]=INF;;
    p[i]=0;
  }
  d[start]=0;
  pq.push(make_pair(0,0));
  while(!pq.empty()){
    pair<int,int> f=pq.top();pq.pop();
    int u=f.second;
    p[u]=1;
    if(d[u]<f.first*(-1)) continue;

    for(int i=0;i<adj[u].size();i++){
      int v=adj[u][i].first;
      if(p[v]) continue;
      if(d[v]>d[u]+adj[u][i].second){
	d[v]=d[u]+adj[u][i].second;
	pq.push(make_pair(d[v]*(-1),v));
      }
    }
  }
  for(int i=0;i<n;i++){
    cout<<i<<" "<<d[i]<<endl;
  }
}


  

    
int main(){
  int u,k,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(0);
  return 0;
}