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 <iomanip>
#include <algorithm>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <functional>
#include <sstream>
#include <string>
#include <utility>
#include <map>
#include <memory>
#include <set>
#include <vector>
#include <deque>
#include <list>
#include <stack>
#include <queue>

using namespace std;

class SSSPath
{
public:
  int solve();
};

int SSSPath::solve()
{
  int n;
  cin >> n;

  vector<vector<pair<int, int>>> adj( n );

  for ( auto i = 0; i < n; ++i )
    {
      int k, u, v, w;

      cin >> u >> k;

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

  const int infty = 2000000000;
  
  vector<int> d( n, infty );
  vector<bool> vs( n, true );
  
  d[0] = 0;

  while ( true )
    {
      int u, mc = infty;

      for ( auto i = 0; i < n; ++i )
        {
          if ( vs[i] && d[i] < mc )
            {
              mc = d[i];
              u = i;
            }
        }

      if ( mc == infty ) break;
      
      vs[u] = false;

      for ( auto it = adj[u].begin(); it != adj[u].end(); ++it )
        {
          if ( d[(*it).first] > d[u] + (*it).second )
            {
              d[(*it).first] = d[u] + (*it).second;
            }
        }
    }

  for ( auto i = 0; i < n; ++i )
    cout << i << " " << d[i] << endl;
  
  return 0;
}

int main()
{
  SSSPath s;

  s.solve();

  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i = 0; i < (int)(n); i++)

#define MAX 10000
#define INF (1<<20)
#define WHITE 0
#define GRAY 1
#define BLACK 2

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

void dijkstra(int s){
    priority_queue<pair<int,int> > PQ;
    int d[MAX], color[MAX];

    rep(i,n){
        color[i] = WHITE;
        d[i] = INF;
    }

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

    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 i = 0; i < adj[u].size(); i++){
            int v = adj[u][i].first;
            int c = adj[u][i].second;
            if(color[v] == BLACK) continue;
            if(d[v] > d[u] + c){
                d[v] = d[u] + c;
                PQ.push(make_pair((-1)*d[v], v));
            }
        }
    }

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

int main(){
    cin >> n;
    int u, k, v, c;
    rep(i,n){
        cin >> u >> k;
        rep(j,k){
            cin >> v >> c;
            adj[u].push_back(make_pair(v, c)); 
        }
    }

    dijkstra(0);

    return 0;
}