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<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(void);

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;

}
      
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;
  }
}

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

struct Edge{
    int from,to;
    Weight weight;
};
using Edges=vector<Edge>;
using Graph=vector<Edges>;

Weight INF=1e9+7;
vector<Weight> Dijkstra(int s,const Graph& g){
    int n=g.size();
    vector<Weight> res(n,INF);
    vector<int> used(n,0);
    res[s]=0;
    priority_queue<pair<Weight,int>,vector<pair<Weight,int>>,greater<>> que;
    que.push({Weight(0),s});
    while(!que.empty()){
        auto p=que.top(); que.pop();
        Weight dist=p.first;
        int v=p.second;
        if(used[v]) continue;
        used[v]=true;
        for(int i=0;i<g[v].size();i++){
            int tdist=dist+g[v][i].weight;
            if(tdist<res[g[v][i].to]){
                res[g[v][i].to]=tdist;
                que.push({tdist,g[v][i].to});
            }
        }
    }
    return res;
}

int main(){
    int n;
    cin>>n;
    Graph g(n);
    for(int i=0;i<n;i++){
        int u,k;
        cin>>u>>k;
        for(int j=0;j<k;j++){
            Edge e;
            e.from=u;
            cin>>e.to>>e.weight;
            g[u].push_back(e);
        }
    }
    auto d=Dijkstra(0,g);
    for(int i=0;i<n;i++){
        cout<<i<<" "<<d[i]<<endl;
    }

    return 0;
}

C++: #include<iostream>
int main(){
  int u,k,C,V,A[1000][1000],D[1000][1000],n;
  std::cin >> n;
  for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j] = 200001;
  for(int i=0;i<n;i++){ 
    std::cin >> u >> k;
    for(int j=0;j<k;j++){
      std::cin >> V >> C;
      D[u][V] = C;
    } 
  }
  for(int i=0;i<n;i++)D[i][i] = 0;
  for(int k=0;k<n;k++)for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j]= std::min(D[i][j],D[i][k] + D[k][j]);
  for(int i=0;i<n;i++)std::cout << i << " " << D[0][i] << std::endl;
  return 0;
}

C++: #include<map>
#include<vector>
#include<cstdio>
using namespace std;
int n,N,i,j,k,c,m;
int main(){
	scanf("%d",&N);
	vector<map<int,int>>dist(N);
	vector<bool>used(N);
	vector<int>cost(N);
	for(;n<N;n++){
		cost[n]=1e9;
		for(scanf("%d%d",&i,&k);k--;dist[i][j]=c)scanf("%d%d",&j,&c);
	}
	for(cost[0]=0;;){
		m=1e9;
		for(i=0;i<N;i++)if(!used[i]&&m>cost[i])m=cost[i];
		if(m==1e9)break;
		for(j=0;j<N;j++)if(m==cost[j]){
			map<int,int>::iterator it=dist[j].begin();
			for(used[j]=1;it!=dist[j].end();it++)if(cost[it->first]>it->second+cost[j])cost[it->first]=it->second+cost[j];
		}
	}
	for(i=0;i<n;i++)printf("%d %d\n",i,cost[i]);
}