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 <stdio.h>
#define INF 1000000
#define white 0
#define black 2
#define gray 1

int n,M[100][100];

void dijkstra();

int main(){
  int i,j,k,c,v,u;
  scanf("%d",&n);
  for(i=0;i<n;i++){ 
    for(j=0;j<n;j++){
      M[i][j]=INF;
    }
  }
  for(i=0;i<n;i++){
    scanf("%d%d",&u,&k);
    for(j=0;j<k;j++){
      scanf("%d%d",&v,&c);
      M[u][v]=c;
    }
  }
  dijkstra();
  
  return 0;
}
void dijkstra(){
  int i,d[100],mincost,color[100],v,u;
  for(i=0;i<n;i++){
    d[i]=INF;
    color[i]=white;
  }
  d[0]=0;
  color[0]=gray;

  while(1){
    mincost=INF;
    u=-1;
    for(i=0;i<n;i++){
      if(color[i]!=black&&d[i]<mincost){
	mincost=d[i];
	u=i;
      }
    }
    if(u==-1)break;
    
    color[u]=black;
    for(v=0;v<n;v++){
      if(color[v]!=black&&M[u][v]!=INF){
	if(d[v]>d[u]+M[u][v]){
	  d[v]=d[u]+M[u][v];
	  color[v]=gray;
	}
      }
    }
  }
  for(i=0;i<n;i++){
    printf("%d ",i);
    if(d[i]==INF)printf("-1");
    else printf("%d",d[i]);
    printf("\n");
  }
}

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

#define MAX 100
#define WHITE 0
#define GRAY 1
#define BLACK 2
int INF = (1<<21);

void dijkstra(void);

int n;
int M[MAX][MAX];

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

void dijkstra(){
  int minV;
  int d[MAX],color[MAX];
  int u,v;
  int i;
  for(i = 0; i < n; i++){
    //d[i] = INFINITY;
    d[i] = INF;
    color[i] = WHITE;
  }
  d[0] = 0;
  color[0] = GRAY;
  while(1){
    //minV = INFINITY;
    minV = INF;
    u = -1;
    for(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(v = 0; v < n; v++){
      //if(color[v] != BLACK && M[u][v] != INFINITY){
      if(color[v] != BLACK && M[u][v] != INF){
        if(d[v] > d[u] + M[u][v]){
          d[v] = d[u] + M[u][v];
          color[v] = GRAY;
        }
      }
    }
  }
  for(i = 0; i < n; i++){
    //cout << i << " " << (d[i] == INFINITY ? -1 : d[i]) << endl;
    cout << i << " " << (d[i] == INF ? -1 : d[i]) << endl;
  }
}

C++: #include<iostream>
#define LEN 100
#define INFTY 2000000001
#define NIL -1
#define WHITE 1
#define BLACK 0
using namespace std;
 
int main()
{
  int n,u,v,k,c,mincost=0;
  int G[LEN+1][LEN+1], d[LEN+1], pi[LEN+1], color[LEN+1];
 
  cin>>n;
 
  for(int i = 0; i < n; i++){
    for(int j = 0; j < n; j++){
      G[i][j] = INFTY;
    }
  }
   
  for(int i = 0; i < n; i++){
    cin>>u>>k;
    for(int j = 0; j < k; j++){
      cin>>v>>c;
      G[u][v] = c;
    }
  }
 
  for(int i = 0; i < n; i++){
    d[i] = INFTY;
    pi[i] = NIL;
    color[i] = WHITE;
  }
   
  d[0] = 0;
   
  while(1){
    mincost = INFTY;
    for(int i = 0; i < n; i++){
      if(color[i] != BLACK && d[i] < mincost){
    mincost = d[i];
    u = i;
      }
    }

    if(mincost == INFTY) break;
    color[u] = BLACK;
    for(int i = 0; i < n; i++){
      if(d[i] > d[u] + G[u][i]){
        d[i] = d[u] + G[u][i];
        pi[i] = u;
      }
    }
  }
 
  for(int i = 0; i < n; i++){
    cout<<i<<" "<<d[i]<<endl;

  }
 
  return 0;
}

C++: #include <iostream>
#include <vector>
#define rep(i,N) for(int i = 0; i<(int)(N); i++)
#define REP(i,k,N) for(int i = k; i<(int)(N); i++)
#define MAX_C 100000
typedef long long ll;
using namespace std;

int main(){
        int n;
        cin >> n;
        vector< vector<int> > G(n, vector<int>(n,MAX_C+1));
        int u,k,v,c;
        rep(i,n){
                cin >> u >>k;
                rep(j,k){
                        cin >> v >> c;
                        G[u][v] = c;
                }
        }

        vector<ll> d(n, MAX_C * n);
        d[0]=0;
        bool update = true;
        while(update) {
                update  = false;
                rep(from,n) {
                        if(d[from] >= MAX_C * n) continue;

                        rep(to,n){
                                if(from == to || G[from][to] >= MAX_C + 1) continue;

                                if(d[to] > d[from] + G[from][to]) {
                                        update = true;
                                        d[to] = d[from] + G[from][to];
                                }

                        }
                }
        }
        rep(i,n){
                cout << i << " " << d[i] << endl;
        }

        return 0;
}