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 s)
{
    int u, minv;
    int color[MAX], d[MAX], p[MAX];
    for (int i = 0; i != n; ++i)
    {
        color[i] = WHITE;
        d[i] = INFTY;
        p[i] = -1;
    }
    d[s] = 0;
    while (true)
    {
        minv = INFTY;
        for (int i = 0; i != n; ++i)
        {
            if (color[i] != BLACK && d[i] < minv)
            {
                u = i;
                minv = d[i];
            }
        }
        if (minv == INFTY)
        {
            break;
        }
        color[u] = BLACK;
        for (int v = 0; v != n; ++v)
        {
            if (M[u][v] != INFTY && color[v] != BLACK)
            {
                if (d[u] + M[u][v] < d[v])
                {
                    d[v] = d[u] + M[u][v];
                    color[v] = GRAY;
                    p[v] = u;
                }
            }
        }
    }
    for (int i = 0; i != n; ++i)
    {
        cout << i << " " << d[i] << endl;
    }
}

int main()
{
    int u, k, v, c;
    cin >> n;
    for (int i = 0; i != n; ++i)
    {
        for (int j = 0; j != n; ++j)
        {
            M[i][j] = INFTY;
        }
    }
    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(0);
    return 0;
}

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

template<typename A, size_t N, typename T>
void Fill(A (&array)[N], const T &val) {
  std::fill((T*)array, (T*)(array + N), val);
}

const int INF = (1 << 21);

int n;
int m[100][100];

void dijikstra()
{
  int minv;
  int d[100], color[100];

  fill(d, d + 100, INF);
  fill(color, color + 100, 0);

  d[0] = 0;
  color[0] = 1;
  while (true) {
    minv = INF;
    int u = -1;
    for (int i = 0; i < n; i++) {
      if (minv > d[i] && color[i] != 2) {
        u = i;
        minv = d[i];
      }
    }
  
    if (u == -1) break;
    color[u] = 2;
  
    for (int v = 0; v < n; v++) {
      if (color[v] != 2 && m[u][v] != INF) {
        if (d[v] > d[u] + m[u][v]) {
          d[v] = d[u] + m[u][v];
          color[v] = 1;
        }
      }
    }
  }
  
  for (int i = 0; i < n; i++) {
    cout << i << " " << (d[i] == INF ? -1 : d[i]) << endl;
  }
}

signed main()
{
  int k, u, v, c;

  Fill(m, INF);

  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> u >> k;
    for (int j = 0; j < k; j++) {
      cin >> v >> c;
      m[u][v] = c;
    } 
  }

  dijikstra();

  return (0);
}

C++: #include <cstdio>
static const int INFTY = (1 << 21);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n, **M;
int *d, *p;

void dijkstra() {
    int u, minv;
    int d[n], p[n], color[n];

    for (int i = 0; i < n; i++) {
        d[i] = INFTY;
        p[i] = -1;
        color[n] = WHITE;
    }
    d[0] = 0;

    while (1) {
        u = -1;
        minv = INFTY;
        for (int i = 0; i < n; i++) {
            if (color[i] != BLACK && d[i] < minv) {
                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) {
                // printf("d[%d] = %d, M[%d][%d] = %d, d[%d] = %d\n", u, d[u], u, v, M[u][v], v, d[v]);
                if (d[u] + M[u][v] < d[v]) {
                    p[v] = u;
                    d[v] = d[u] + M[u][v];
                    color[v] = GRAY;
                }             
            }
        }
    }
    
    for (int i = 0; i < n; i++) {
        printf("%d %d\n", i, d[i]);
    }
}

int main() {
    scanf("%d", &n);

    M = new int*[n];
    for (int i = 0; i < n; i++) {
        M[i] = new int[n];
        for (int j = 0; j < n; j++) {
            M[i][j] = INFTY;
        }
    }

    for (int i = 0; i < n; i++) {
        int u, k;
        scanf("%d %d", &u, &k);
        for (int j = 0; j < k; j++) {
            int v, c;
            scanf("%d %d", &v, &c);
            M[u][v] = c;
            printf("");
        }
    }

    dijkstra();

    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
static const int MAX = 100; 
int n,M[MAX][MAX];
void dij(){
	int minv;
	int d[MAX],color[MAX];
	for(int i = 0;i < n;i++){
		d[i] = INT_MAX;
		color[i] = 0;
	}
	d[0] = 0;
	color[0] = 1;
	while(1){
		minv = INT_MAX;
		int u = -1;
		for(int i = 0;i < n;i++){
			if(minv > d[i] && color[i] != 2){
				u = i;
				minv = d[i];
			}
		}
		if(u == -1)break;
		color[u] = 2;
		for(int v = 0; v < n; v++){
			if(color[v] != 2 && M[u][v] != INT_MAX){
				if(d[v] > d[u] + M[u][v]){
					d[v] = d[u] + M[u][v];
					color[v] = 1;
				}
			}
		}
	}
	for(int i = 0;i < n;i++){
		cout << i << " " << (d[i] == INT_MAX ? -1 : d[i]) << endl;
	}
}
int main(){
	cin >> n;
	for(int i = 0;i < n;i++){
		for(int k = 0;k < n;k++){
			M[i][k] = INT_MAX;
		}
	}
	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;
		}
	}
	dij();
}