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++: #include<iostream>
#include<queue>
using namespace std;

struct Edge {
  /*
    dst -> destination
    weight -> weight
   */
  int dst,weight;
};

struct Data {

  int place,min;

  bool operator < (const Data& data)const{
    //if( min < data.min ) => true;
    if(data.min != min)return min > data.min;
    return data.place > place;
  }

};

//int cost[100001][100001];
vector<Edge> cost[10001];
int n;
int mindist[10001];
bool used[10001];

void dijkstra(){

  for(int i=0 ; i < 10001 ; i++){
    mindist[i]=1e9;
  }
  
  mindist[0]=0;

  priority_queue<Data> PQ;

  PQ.push((Data){0,0});

  while(!PQ.empty()){
    Data a=PQ.top();
    PQ.pop();
    if( mindist[a.place] < a.min ) continue;
    for(int i=0 ; i < (int)cost[a.place].size() ; i++){
      if(mindist[cost[a.place][i].dst] > cost[a.place][i].weight+mindist[a.place]){
	mindist[cost[a.place][i].dst] = cost[a.place][i].weight+mindist[a.place];
	PQ.push((Data){cost[a.place][i].dst,mindist[cost[a.place][i].dst]});
      }
      //cost[a.place].pop_back();
    } 
  }
  
  for(int i=0 ; i < n ; i++){
    cout <<i<<" "<<mindist[i]<<endl;
  }
  
}
int main(){
  
  int u,k,v,c;
  
  // 0 -> 1 weight : 3
  /*  
      cost[0].push_back((Edge){1,3});
      cost[0].push_back((Edge){0,4});
      cost[2].push_back((Edge){0,3});
  */
  
  cin >>n;
  
  for(int i=0 ; i < n ; i++){
    cin >>u>>k;
    for(int j=0 ; j < k ; j++){
      cin >>v>>c;
      cost[u].push_back((Edge){v,c});
    }
  }

  dijkstra();

  return 0;
}


/*
1sec => 10^8


 */

C++: #include <algorithm>
#include <iostream>
#include <vector>
using namespace std;
const long long INF = 1LL << 60;    // 1.15x10^18
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

using edge = pair<int, long long>;
using Graph = vector<vector<edge>>;

vector<long long> dijkstra(const Graph &g, int s) {
    int n = g.size();
    vector<long long> dist(n, INF);
    vector<bool> fixed(n);
    dist[s] = 0;
    while (true) {
        int u = -1;
        for (int i = 0; i < n; i++) if (!fixed[i]) {
            if (u == -1 || dist[i] < dist[u]) u = i;
        }
        if (u == -1) break;
        fixed[u] = true;
        for (auto &e: g[u]) chmin(dist[e.first], dist[u] + e.second);
    }
    return dist;
}

int main() {
    int V; cin >> V;
    Graph g(V);
    for (int i = 0; i < V; i++) {
        int u, k; cin >> u >> k;
        while (k--) {
            int v, c; cin >> v >> c;
            g[u].emplace_back(v, c);
        }
    }
    auto dist = dijkstra(g, 0);
    for (int u = 0; u < V; u++) cout << u << " " << dist[u] << endl;
    return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<queue>
#include<vector>
#include<stdio.h>
using namespace std;

static const int INFTY = (1<<21);
enum Color{
    WHITE,
    GRAY,
    BLACK
};
int n;

//int M[100][100];
vector<pair<int,int> > adj[10000];   //隣接リスト
priority_queue<pair<int, int> > PQ; 
Color color[10000];
int d[10000];

void dijkstra(){
    for(int i=0; i<n; i++){
        color[i] = WHITE;
        d[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, size = adj[u].size(); j<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(){

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

    dijkstra();
    return 0;
}