Go: package main

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

const (
	white int = iota
	gray
	black
)

type node struct {
	id     int
	parent int
	edge   []int
	weight []int
	color  int
}

type graph struct {
	nodes    []node
	distance []int
}

var infty = 1 << 32
var null = -1

func constructgraph() *graph {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n := nextInt(sc)

	g := &graph{make([]node, n), make([]int, n)}

	for i := 0; i < n; i++ {
		id := nextInt(sc)
		edges := nextInt(sc)
		n := node{}
		n.id = id
		n.edge = make([]int, edges)
		n.weight = make([]int, edges)
		n.color = white
		for j := 0; j < edges; j++ {
			to := nextInt(sc)
			w := nextInt(sc)
			n.edge[j] = to
			n.weight[j] = w
		}
		g.nodes[id] = n
	}
	return g
}

func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

func (g *graph) preparedijkstra(s int) {
	for i := 0; i < len(g.nodes); i++ {
		g.nodes[i].color = white
		g.nodes[i].parent = null
		g.distance[i] = infty
	}
	g.distance[s] = 0
}

func (g *graph) dijkstra(s int) []int {
	g.preparedijkstra(s)

	for {
		var u int
		mincost := infty
		for i, d := range g.distance {
			if g.nodes[i].color != black && mincost > d {
				mincost = d
				u = i
			}
		}

		if mincost == infty {
			break
		}

		g.nodes[u].color = black

		for i, e := range g.nodes[u].edge {
			if g.nodes[e].color != black {
				if g.distance[e] > g.distance[u]+g.nodes[u].weight[i] {
					g.distance[e] = g.distance[u] + g.nodes[u].weight[i]
					g.nodes[e].parent = u
					g.nodes[e].color = gray
				}
			}
		}
	}
	return g.distance
}

func printShortestPath(d []int) {
	for i, v := range d {
		fmt.Printf("%d %d\n", i, v)
	}
}

func main() {
	g := constructgraph()
	d := g.dijkstra(0)
	printShortestPath(d)
}

C++: #include<iostream>
#include<cstdio>
#include<cstring>
#define INF 1<<20
using namespace std;
int n;
int A[1000][1000];
int d[1000];
bool used[1000];
int D[1000][1000];

void Init(int f){
  for(int i=0;i<f;i++){
    for(int j=0;j<f;j++)D[i][j] = INF;
  }

}

void djkstra(){
  for(int i=0;i<n;i++){
    d[i] = INF;
    used[i] = false;
  }
  d[0] = 0;

  while(true){
    int v = -1;
    for(int i=0;i<n;i++){
      if(!used[i] && (v == -1 || d[v] > d[i]))v = i;
    }
    if(v == -1)break;
    used[v] = true;
    for(int i=0;i<n;i++){
      d[i] = min(d[i],d[v] + D[v][i]);
    }
  }
}



int main(){
  scanf("%d",&n);
  int u,k,C,V;
  Init(n);
 
  for(int i=0;i<n;i++){
      scanf("%d %d",&u,&k);     
      for(int j=0;j<k;j++){
	scanf("%d %d",&V,&C);
	D[u][V] = C;
	D[V][u] = C;
      }     
  }
  
  //for(int i=0;i<n;i++)D[i][i] = 0;
  //for(int k=0;k<n;k++)for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j] = min(D[i][j],D[i][k] + D[k][j]);

  djkstra();
 
  for(int i=0;i<n;i++){
    printf("%d %d\n",i,d[i]);
  }

  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define M 1000000007
#define ff first.first
#define fs first.second
#define sf second.first
#define ss second.second
typedef pair<int,int> P;
typedef pair<P,P> PP;
int main(void)
{
	int i,j,k,u,n,flg[101],v,c,sum,ky[101],t,min,g;
	PP ke[101];
	scanf("%d",&n);
	sum=0;
	for(i=0;i<n;i++) ky[i]=M,flg[i]=0;
	ky[0]=0;
	for(i=0;i<n;i++){
		scanf("%d%d",&u,&k);
		for(j=sum;j<k+sum;j++){
			scanf("%d%d",&v,&c);
			ke[j].ff=u , ke[j].fs=v , ke[j].sf=c;
		}
		sum+=k;
	}
	sort(ke,ke+sum);
	//for(i=0;i<sum;i++) printf("ke[%d].ff=%d ke[%d].fs=%d ke[%d].sf=%d\n",i,ke[i].ff,i,ke[i].fs,i,ke[i].sf);
	for(i=0;i<sum;i++){
		min=M;
		for(j=0;j<sum;j++) if(flg[j]==0&&min>ky[j]) g=j,min=j;
		flg[g]=1;
		if(min==M) break;
		for(j=0;j<sum;j++){
			t=ky[ke[j].ff]+ke[j].sf;
			if(ky[ke[j].fs]>t) g=j,ky[ke[j].fs]=t;
		}
	}
	for(i=0;i<n;i++) printf("%d %d\n",i,ky[i]);
	return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cassert>
#include <string>
#include <cstring>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <algorithm>

using namespace std;

// ---------------------
// repetition
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)

// debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

// ---------------------
#define INF (1 << 21)
typedef long long ll;

int main() {
  int n;
  cin >> n;

  vector<int> V[n];
  int E[n][n];
  int d[n];
  int visited[n];

  REP(x, n) {
    REP(y, n) {
      E[x][y] = INF;
    }
    d[x] = INF;
    visited[x] = 0;
  }

  REP(_, n) {
    int u, k;
    cin >> u >> k;
    REP(__, k) {
      int v, c;
      cin >> v >> c;
      V[u].push_back(v);
      E[u][v] = c;
      E[v][u] = c;
    }
  }

  d[0] = 0;
  REP(_, n) {
    int minv = -1;
    int mincost = INF;
    REP(v, n) {
      if (!visited[v] && d[v] < mincost) {
        minv = v;
        mincost = d[v];
      }
    }
    visited[minv] = 1;
    for (vector<int>::iterator it = V[minv].begin(); it != V[minv].end(); it++) {
      if (E[minv][*it] < INF && d[minv] + E[minv][*it] < d[*it]) {
        d[*it] = d[minv] + E[minv][*it];
      }
    }
  }

  REP(i, n) {
    cout << i << " " << d[i] << endl;
  }
  return 0;
}

C++: #include <iostream>
#include <climits>

using namespace std;
#define MAX 100
#define WHITE 0
#define BLACK 1

int W[MAX][MAX],color[MAX],d[MAX],p[MAX];
int n,u,k,v,c;

int Djs()
{
   int minv,u;
   d[0]=0;
   while(1)
   {
    minv=INT_MAX;
     u=-1;
    for(int i=0;i<n;i++)
    {
       if(d[i]<minv&&color[i]!=BLACK)
       {
           minv=d[i];
           u=i;
       }
    }
    if(u==-1) break;
    color[u]=BLACK;
    for(int v=0;v<n;v++)
    {
       if(W[u][v]!=INT_MAX&&color[v]!=BLACK)
       {
           if(d[u]+W[u][v]<d[v])
           {
               d[v]=d[u]+W[u][v];
               p[v]=u;
           }
       }
    }
   }
   for(int i=0;i<n;i++)
   {
       cout<<i<<" "<<d[i]<<endl;
   }
}

int main()
{
    cin>>n;
    for(int i=0;i<n;i++)
    {
     d[i]=INT_MAX;
     p[i]=-1;
     for(int j=0;j<n;j++)
     {
        W[i][j]=INT_MAX;
     }
    }
    for(int i=0;i<n;i++)
    {
     cin>>u>>k;
     for(int j=0;j<k;j++)
     {
        cin>>v>>c;
        W[u][v]=c;
     }
    }
    Djs();
    return 0;
}