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;

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 << " ";
    if(d[i] == INFTY) cout << -1 << endl;
    else cout << 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>
using namespace std;
#define N 100
static const int infinity =(1<<21);
static const int white =0;
static const int gray = 1;
static const int black =2;

int n,M[N][N];

void dijkstra(){
    int min,u;
    int color[N],d[N];
    
    for(int i=0;i<n;i++){
        color[i]=white;
        d[i]=infinity;
    }
    
    d[0]=0;
    
    while(1){
        min=infinity;
        int u=-1;
        for(int i=0;i<n;i++){
            if(color[i]!=black&&d[i]<min){
                min=d[i];
                u=i;
            }
        }
        if(min==infinity)break;
        
        color[u]=black;
        
        for(int v=0;v<n;v++){
            if(color[v]!=black&&M[u][v]!=infinity){
                if(d[u]+M[u][v]<d[v]){
                    d[v]=d[u]+M[u][v];
                    color[v]=gray;
                }
            }
        }
    }
    for(int i=0;i<n;i++)cout<<i<<" "<<d[i]<<endl;
}

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

C++: #include <iostream>
#include <vector>
#include <queue>
#include <functional>
#include <string.h>

using namespace std;
static const int INF = 1e9;
typedef pair<int, int> P;
struct edge
{
	int to;
	int cost;
};

int d[101];
vector<edge> G[101];

void solve()
{
	int n;
	cin >> n;
	for (int i = 0; i < n; ++i)
	{
		int u, k;
		cin >> u >> k;
		for (int j = 0; j < k; ++j)
		{
			int to, cost;
			cin >> to >> cost;
			edge e1, e2;
			e1.to = to;
			e1.cost = cost;
			e2.to = u;
			e2.cost = cost;
			G[u].push_back(e1);
			G[to].push_back(e2);
		}
	}
	for (int i = 0; i < 101; ++i)
	{
		d[i] = INF;
	}
	d[0] = 0;
	priority_queue<P, vector<P>, greater<P> > pque;
	pque.push(P(0, 0));
	while (!pque.empty())
	{
		P p = pque.top();
		pque.pop();
		int v = p.second;
		for (int i = 0; i < G[v].size(); ++i)
		{
			edge e = G[v][i];
			if (d[e.to] > d[v] + e.cost)
			{
				d[e.to] = d[v] + e.cost;
				pque.push(P(d[e.to], e.to));
			}
		}
	}
	for (int i = 0; i < n; ++i)
	{
		cout << i << " " << d[i] << endl;
	}
}

int main()
{
	solve();
	return(0);
}

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 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;
}