Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

var infty = 1000000000

type DirectedGraphNodeID int

type DirectedGraphNode struct {
	key         DirectedGraphNodeID
	adjacents   []*DirectedGraphNode
	costs       []int
	distance    int
	predecessor *DirectedGraphNode
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]*DirectedGraphNode, nNodes)
	for i := 0; i < nNodes; i++ {
		node := DirectedGraphNode{}
		node.key = DirectedGraphNodeID(i)
		node.distance = infty
		graph.nodes[i] = &node
	}
	return &graph
}

type DirectedGraph struct {
	nodes []*DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(i, j DirectedGraphNodeID, cost int) {
	g.nodes[i].adjacents = append(g.nodes[i].adjacents, g.nodes[j])
	g.nodes[i].costs = append(g.nodes[i].costs, cost)
}

func (g *DirectedGraph) print() {
	for i := 0; i < len(g.nodes); i++ {
		node := g.nodes[i]
		key := node.key
		strings := []string{strconv.Itoa(int(key)), strconv.Itoa(node.distance)}
		for j := 0; j < len(node.adjacents); j++ {
			nodeJ := fmt.Sprintf("(%v, %v)", node.adjacents[j].key, node.costs[j])
			strings = append(strings, nodeJ)
		}
		fmt.Printf("%v\n", strings)
	}
}

func (g *DirectedGraph) relaxEdge(l, r *DirectedGraphNode, w int) {
	if r.distance > l.distance+w {
		// fmt.Printf("%v -> %v, %v\n", l.key, r.key, l.distance+w)
		r.distance = l.distance + w
		r.predecessor = l
	}
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	graph := newDirectedGraph(nNodes)

	for i := 0; i < nNodes; i++ {
		iNode := DirectedGraphNodeID(nextInt())
		nAdjacent := nextInt()
		for j := 0; j < nAdjacent; j++ {
			jNode := DirectedGraphNodeID(nextInt())
			cost := nextInt()
			graph.setAdjacency(iNode, jNode, cost)
		}
	}

	graph.nodes[0].distance = 0
	for iNode := 0; iNode < nNodes; iNode++ {
		for iLeft := 0; iLeft < len(graph.nodes); iLeft++ {
			nodeLeft := graph.nodes[iLeft]
			for iRight := 0; iRight < len(nodeLeft.adjacents); iRight++ {
				nodeRight := nodeLeft.adjacents[iRight]
				cost := nodeLeft.costs[iRight]
				graph.relaxEdge(nodeLeft, nodeRight, cost)
			}
		}
	}

	// graph.print()

	for iNode := 0; iNode < len(graph.nodes); iNode++ {
		node := graph.nodes[iNode]
		fmt.Println(node.key, node.distance)
	}
}

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

const int N=100;
const int INF=2000000000;
const int WHITE=0;
const int GRAY=1;
const int BLACK=2;

int n,M[N][N],d[N],color[N];

void dijkstra(){
    d[0]=0;
    color[0]=GRAY;
    while(true){
        int min_des=INF;
        int vertex=-1;
        for(int i=0;i<n;i++){
            if(min_des>d[i]&&color[i]==GRAY){
                min_des=d[i];
                vertex=i;
            }
        }
        if(vertex==-1) break;
        color[vertex]=BLACK;
        for(int i=0;i<n;i++){
            if(color[i]!=BLACK&&M[vertex][i]<INF){
                if(d[i]>d[vertex]+M[vertex][i]){
                    d[i]=d[vertex]+M[vertex][i];
                    color[i]=GRAY;
                }
            }
        }
    }
}        

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]=INF;
        }
        d[i]=INF;
        color[i]=WHITE;
    }
    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();

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

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);
}