Go: package main

import (
	"bufio"
	"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
type Node struct {
	cost int
	done bool
}

type Edge struct {
	to, cost int
}

const INF = 1 << 60

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	nodes := make([]Node, N)
	for i := 0; i < N; i++ {
		nodes[i].cost = INF
	}
	E := make([][]Edge, N)
	for i := 0; i < N; i++ {
		id, k := sc.nextInt(), sc.nextInt()
		for j := 0; j < k; j++ {
			to, cost := sc.nextInt(), sc.nextInt()
			E[id] = append(E[id], Edge{to, cost})
		}
	}
	nodes[0].cost = 0
	for {
		cur := 0
		minCost := INF
		for i := 0; i < N; i++ {
			n := nodes[i]
			if !n.done && n.cost < minCost {
				cur = i
				minCost = n.cost
			}
		}
		if minCost == INF {
			break
		}
		nodes[cur].done = true
		for i := 0; i < len(E[cur]); i++ {
			to, cost := E[cur][i].to, E[cur][i].cost+nodes[cur].cost
			if !nodes[to].done && cost < nodes[to].cost {
				nodes[to].cost = cost
			}
		}
	}

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

C++: #include<iostream>
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 minv;
	int 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 ) {
		minv = INFTY;
		int u = -1;
		for (int i = 0; i < n; i++ ) {
			if ( minv > d[i] && color[i] != BLACK ) {
				u = i;
				minv = d[i];
			}
		}
		if ( u == -1 ) break;
		color[u] = BLACK;
		for (int v = 0; v < n; v++ ) {
			if ( color[v] != BLACK && M[u][v] != INFTY ) {
				if (d[v] > d[u] + M[u][v] ) {
					d[v] = d[u] + M[u][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++) {
		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;
}

C++: #include<iostream>
#include<vector>
#define INF (1<<21)
#define WHITE 1
#define BLACK 2
#define GRAY 3
#define neg -1
using namespace std;

int n;
int m[100][100];
vector<int> g;
vector<int> color;

void di(){
  int u, mincost;

  for(int i = 0; i < n; i++){
    g[i] = INF;
    color[i] = WHITE;
  }

  g[0] = 0;
  color[0] = GRAY;

  while(1){
    mincost = INF;
    u = -1;

    for(int i = 0; i < n; i++){
      if(mincost > g[i] && color[i] != BLACK){
	u = i;
	mincost = g[i];
      }
    }

    if(u == neg) break;

    color[u] = BLACK;

    for(int i = 0; i < n; i++){
      if(color[i] != BLACK && m[u][i] != INF){
	if(g[i] > (g[u] + m[u][i])){
	  g[i] = g[u] + m[u][i];
	  color[i] = GRAY;
	}
      }
    }
  }

  for(int i = 0; i < n; i++){
    cout << i << " " << (g[i] == INF ? neg:g[i]) << endl;

  }
}

int main()
{
  cin >> n;
  g.resize(n);
  color.resize(n);

  for(int i = 0; i < n; i++){
    for(int j = 0; j < n; j++){
      m[i][j] = INF;
    }
  }

  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;
    }
  }

  di();

  return 0;

}

C++: #include<iostream>
#include<vector>
using namespace std;
const int MAX = 100;
const int INF = 10000000;
int n, G[MAX][MAX];
int dis[MAX];
bool Flag[MAX] = { false };
void init()
{
	for (int i = 0; i < n; i++)
		dis[i] = G[0][i];
	Flag[0] = true;
}
void dijkstra()
{
	for (int k = 1; k <= n - 1; k++)
	{
		int min = INF;
		int u;
		for (int j = 0; j < n; j++)
			if (dis[j] > 0 && dis[j] < INF && !Flag[j] && dis[j] < min)
			{
				min = dis[j];
				u = j;
			}
		Flag[u] = true;
		for (int v = 0; v < n; v++)
			if (!Flag[v] && dis[u]+G[u][v] < dis[v])
				dis[v] = dis[u] + G[u][v];
	}
}
int main()
{
	cin >> n;
	for (int i = 0; i < n; i++)
		for (int j = 0; j < n; j++)
			if (i != j)
				G[i][j] = INF;
			else
				G[i][j] = 0;
	for (int i = 0; i < n; i++)
	{
		int u, d;
		cin >> u >> d;
		for (int j = 0; j < d; j++)
		{
			int v, w;
			cin >> v >> w;
			G[u][v] = w;
		}
	}
	init();
	dijkstra();
	for (int i = 0; i < n; i++)
		cout << i << " " << dis[i] << endl;
}

C++: #include<stdio.h>
main()
{
  int i,j,n,g,count=0;
  int V,A,A1,V1;
  int G[101][101],c[101],INF[101],p[101],mincost;

  for(i = 0; i < 101; i++){
    for(j = 0; j < 101; j++)
      G[i][j] = -1;
  }

  scanf("%d",&n);

  for(i = 0; i < n; i++){
    scanf("%d%d",&V,&A);
    for(j = 0; j < A; j++){
      scanf("%d%d",&V1,&A1);
      G[A][A1] = A1;
    }
  }

  for(i = 0; i < n; i++){
    c[i] = 0;
    p[i] = -1;
    INF[i] = 10000001;
  }

  INF[0] = 0;

  while(1){
    mincost = 10000001;
    for(i = 0; i < n; i++){
      if(c[i] != 2 && INF[i] < mincost){
        mincost = INF[i];
        g = i;
      }
    }
    if(mincost == 10000001)break;

    c[g] = 2;


    for(i = 0; i < n; i++){
      if(G[g][i] != -1 && c[i] != 2 && (G[g][i]+INF[g]) < INF[i]){
        p[i] = g;
        INF[i] = G[g][i] + INF[g];
        c[i] = 1;
      }
    }
  }
INF[0] = 0;

  while(1){
    mincost = 10000001;
    for(i = 0; i < n; i++){
      if(c[i] != 2 && INF[i] < mincost){
        mincost = INF[i];
        g = i;
      }
    }
    if(mincost == 10000001)break;

    c[g] = 2;


    for(i = 0; i < n; i++){
      if(G[g][i] != -1 && c[i] != 2 && (G[g][i]+INF[g]) < INF[i]){
        p[i] = g;
        INF[i] = G[g][i] + INF[g];
        c[i] = 1;
      }
    }
  }
  for(i = 0; i < n; i++)printf("%d %d\n",i,INF[i]);
  return 0;
}