Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)

	g := makeGraph(n)
	for i := 0; i < n; i++ {
		u := getNextInt(scanner)
		k := getNextInt(scanner)
		for ii := 0; ii < k; ii++ {
			v := getNextInt(scanner)
			c := getNextInt(scanner)
			g[u][v] = c
		}
	}

	ans := make([]int, n)
	im := make(IntMap, 1)
	im.increment(0)
	for len(im) < n {
		min := 1 << 30
		x := -1
		for u := range im {
			for v := 0; v < n; v++ {
				if im.get(v) != 0 {
					continue
				}
				if min > ans[u]+g[u][v] {
					min = ans[u] + g[u][v]
					x = v
				}
			}
		}
		im.increment(x)
		ans[x] = min
	}

	for i := 0; i < n; i++ {
		fmt.Fprintln(writer, fmt.Sprintf("%d %d", i, ans[i]))
	}
	writer.Flush()
}

func makeGraph(n int) [][]int {
	g := make([][]int, n)
	for i := 0; i < n; i++ {
		g[i] = make([]int, n)
		for ii := 0; ii < n; ii++ {
			g[i][ii] = 1 << 30
		}
	}

	return g
}

// IntMap ...
type IntMap map[int]int

func (m IntMap) get(key int) int {
	if _, ok := m[key]; ok {
		return m[key]
	}
	return 0
}
func (m IntMap) increment(key int) {
	if _, ok := m[key]; ok == false {
		m[key] = 0
	}
	m[key]++
}

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

static const int MAX=100;
static const int INFTY=(1<<21);
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;

int n,m[MAX][MAX];

void dijkstra(){
    int min,d[MAX],color[MAX];
    
    for(int i=0;i<n;i++){
        d[i]=INFTY;
        color[i]=WHITE;
    }
    d[0]=0;
    color[0]=GRAY;
    while(1){
        min=INFTY;
        int u=-1;
        for(int i=0;i<n;i++){
            if(min>d[i] && color[i]!=BLACK){
                u=i;
                min=d[i];
            }
        }
        if(u==-1) break;
        color[u]=BLACK;
        for(int j=0;j<n;j++){
            if(color[j]!=BLACK && m[u][j]!=INFTY){
                if(d[j]>d[u]+m[u][j]){
                    d[j]=d[u]+m[u][j];
                    color[j]=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++){
    for(int j=0;j<n;j++){
        m[i][j]=INFTY;
    }
  }
  int k,c,u,v;
  for(int i=0;i<n;i++){
      cin >> u >> k;
      for(int j=0;j<k;j++){
          cin >> v >> c;
          m[u][v]=c;
      }
  }
  dijkstra();

  return 0;
}