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 20000 
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;
  }
 
}
 
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]);
  for(int i=0;i<n;i++){
    printf("%d %d\n",i,D[0][i]);
  }
 
  return 0;
}

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

const static int MAX = 100;
const static int INF = 1001001001;
int A[MAX][MAX];
int d[MAX];
int p[MAX];
int color[MAX];

int main(void){
    int n, u, k, v, c, mincost, sum;
    std::cin >> n;
    for(int i = 0; i < n; i++){
	for(int j = 0; j < n; j++){
	    A[i][j] = INF;
	}
    }
    for(int i = 0; i < n; i++){
	std::cin >> u >> k;
	for(int j = 0; j < k; j++){
	    std::cin >> v >> c;
	    A[u][v] = c;
	}
    }

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

    while(true){
	mincost = INF;
	for(int i = 0; i < n; i++){
	    if(mincost > d[i] && color[i] == 0){
		mincost = d[i];
		u = i;
	    }
	}
	color[u] = 1;

	if(mincost == INF) break;

	for(int i = 0; i < n; i++){
	    if(d[i] > d[u] + A[u][i] && color[i] == 0){
		d[i] = d[u] + A[u][i];
		p[i] = u;
	    }
	}
    }

    sum = 0;
    for(int i = 0; i < n; i++){
	color[i] = 0;
    }
    for(int i = 0; i < n; i++){
	int cur = i;
	while(p[cur] != -1 && color[cur] == 0){
	    sum += A[p[cur]][cur];
	    color[cur] = 1;
	    cur = p[cur];
	}
    }
    for(int i = 0; i < n; i++){
	std::cout << i << " " << d[i] << std::endl;
    }



    return 0;
}

C++: #include <iostream>
#include <queue>
#include <algorithm>
#include <vector>
#include <climits>
#define int long long
using namespace std;
typedef pair <int,int> P;
#define to first
#define co second
#define fi first
#define se second
const int INF=INT_MAX;
const int MAX_V=100000;
vector <P> G[MAX_V];
int v,d[MAX_V];
void dijk(int s){
  priority_queue <P,vector<P>,greater<P> > que;
  fill(d,d+v,INF);
  d[s]=0;
  que.push(P(0,s));
  for(;!que.empty();){
    P p=que.top(); que.pop();
    int v=p.se;
    if (d[v]<p.fi) continue;
    for(int i=0;i<(int)G[v].size();i++){
      P e=G[v][i];
      if(d[e.to]>d[v]+e.co){
	d[e.to]=d[v]+e.co;
	que.push(P(d[e.to],e.to));
      }
    }
  }
}
signed main(){

  cin>>v;
  for(int i=0,u,k;i<v&&cin>>u>>k;i++) for(int j=0,a,b;j<k&&cin>>a>>b;j++) G[u].push_back(P(a,b));
  dijk(0);
  for(int i=0;i<v;i++) cout<<i<<" "<<d[i]<<endl;
  return 0;

}

C++: #include <iostream>
#include <sstream>
#include <iomanip>
#include <algorithm>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <climits>

#define LP(i,n) for(int i=0;i<n;i++)
#define Mset(x,v) memset(x,v,sizeof(x))

using namespace std;
using LL=long long;

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;
}

C++: #include <iostream>
#include <vector>
#include <queue>
using namespace std;
typedef vector <int> vi;
typedef vector <vi> vvi;

class blanch{
	public:
		int weight;
		int total;
		int from;
		int to;
		blanch():
			weight(0), from(0), to(0){};
		blanch(int newweight, int newfrom, int newto):
			weight(newweight), from(newfrom), to(newto){};
};
typedef vector <blanch> vb;


bool operator<( const blanch &blanch1, const blanch &blanch2){
	return (blanch1.weight > blanch2.weight);
	}

bool operator>( const blanch &blanch1, const blanch &blanch2){
	return (blanch1.weight < blanch2.weight);
	}

int make_graph(vvi &graph, vi &stamp){
	int n=graph.size();
	for (int i=0; i<n; i++){
		for (int j=0; j<n; j++){
			graph[i][j]=0;
		}
	}

	for (int j=0; j<n; j++){
		int i2,n2;
		cin>>i2;
		cin>>n2;
		for (int i=0; i<n2; i++){
			int j2;
			cin>>j2;
			cin>>graph[i2][j2];
		}
		stamp[i2] = -1;
	}
	return 0;
}

int Shortest_Path(vvi &graph, vi &stamp){

	priority_queue<blanch, vb, less<vb::value_type> > pq;
	int n = graph.size(), p1=0;
	stamp[p1] = 0;

	while (p1!=-1){
		for (int p2=0; p2<n; p2++){
			int *tmp = &graph[p1][p2];
			if (*tmp!=0 && stamp[p2]==-1){
				pq.push(blanch(*tmp+stamp[p1], p1, p2));
			}
		}
		p1 = -1;
		while (! pq.empty()){
			blanch tmp = pq.top();
			if (stamp[tmp.from]!=-1 && stamp[tmp.to]==-1){
				p1 = tmp.to;
				stamp[p1] = tmp.weight;
				pq.pop();
				break;
			} else
				pq.pop();
		}
	}
	return 0;
}

int resultout(vi &stamp){
	int n = stamp.size();
	for (int i=0; i<n; i++){
		cout<<i<<" "<<stamp[i]<<endl;
	}
	return 0;
}

int main(void){

	int n;
	cin>>n;
	vvi G(n, vi(n));
	vi stamp(n);

	make_graph(G, stamp);

	Shortest_Path(G, stamp);

	resultout(stamp);

	return 0;
}