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 <bits/stdc++.h>
using namespace std;
using P = pair<int, int>;

const int INF = INT_MAX/2;

struct Edge{
  int to;
  int cost;
  Edge():to(0),cost(0){}
  Edge(int to, int cost):to(to),cost(cost){}
  bool operator<(const Edge& e)const{
    return cost < e.cost;
  }
};

void dijkstra(const int start, const vector< vector<Edge> >& G1, vector< vector<int> >& G2){
  for(int i = 0;  i < G2[start].size(); i++){
    G2[start][i] = INF;
  }

  G2[start][0] = 0;

  priority_queue< P > que; //cost, pos
  que.push(P(0, start));
  while(!que.empty()){
    P p = que.top(); que.pop();
    int pos = p.second;
    int cost = p.first;
    if(G2[start][pos] < cost) continue;
    for(int i = 0; i < G1[pos].size(); i++){
      int to = G1[pos][i].to;
      if(G2[start][to] > G2[start][pos] + G1[pos][i].cost){
        G2[start][to] = G2[start][pos] + G1[pos][i].cost;
        que.push(P(G2[start][to], to));
      }
    }
  }
}

int main(void){
  int n;
  cin >> n;
  vector< vector< Edge > >G(n);
  for(int i = 0; i < n; i++){
    int u, k; cin >> u >> k;
    for(int j = 0; j < k; j++){
      int v, c; cin >> v >> c;
      G[u].push_back(Edge(v, c));
    }
  }
  vector< vector<int> > ans(1, vector<int>(n));
  dijkstra(0, G, ans);
  for(int i = 0; i < n; i++) cout << i << " " << ans[0][i] << endl;

  return 0;
}

C++: #include <iostream>
#define N 100
#define INFINITY 2000000000
using namespace std;
int n,k,u,v,c,M[N][N],d[N],p[N],mincost,i,j;
string color[N];
void dijkstra(void);
int main(){
  cin >> n;
  for(i=0;i<n;i++){
    for(j=0;j<n;j++){
      M[i][j]=-1;
    }
  }
  for(i=0;i<n;i++){
    cin >> u;
    cin >> k;
    for(j=0;j<k;j++){
      cin >> v >> c;
      M[u][v]=c;
    }
  }
  dijkstra();
  return 0;
}
void dijkstra(){
  for(i=0;i<n;i++) color[i]="WHITE",d[i]=INFINITY;
  d[0]=0;
  p[0]=-1;
  while(1){
    mincost=INFINITY;
    for(i=0;i<n;i++){
      if(color[i]!="BLACK"&&d[i]<mincost){
	mincost=d[i];
	u=i;
      }
    }
    if(mincost==INFINITY) break;
    color[u]="BLACK";
    for(i=0;i<n;i++){
      if(color[i]!="BLACK"&&M[u][i]!=-1){
	if(d[u]+M[u][i]<d[i]){
	  d[i]=d[u]+M[u][i];
	  p[i]=u;
	  color[i]="GLAY";
	}
      }
    }
  }
  for(i=0;i<n;i++) cout << i << ' ' << d[i] << endl;
}

C++: #include <bits/stdc++.h>
#define rep(i,a) for(i=0;i<a;i++)
using namespace std;
static const int W = 0;
static const int B = 1;

void dijkstra(int n, vector<vector<int> > &M) {
    int i,u,min;
    vector<int> d(n);
    vector<int> p(n);
    vector<int> color(n);

    rep(i,n){
        d[i] = INT_MAX;
        p[i] = -1;
        color[i] = W;
    }
    d[0] = 0;
    while(true){
        min = INT_MAX;
        rep(i,n){
            if(min > d[i] && color[i] != B) {
                u = i;
                min = d[i];
            }
        }
        if(min == INT_MAX) break;
        color[u] = B;
        rep(i,n){
            if(color[i] != B && M[u][i] + d[u] < d[i]) {
                p[i] = u;
                d[i] = M[u][i] + d[u];
            }
        }
    }
    rep(i,n){
        cout << i << " " << d[i] << endl;
    }
}

int main(void) {
    int i,j,n,u,k,v;
    vector<vector<int> > M;
    cin >> n;
    M.resize(n);

    rep(i,n){
        M[i].resize(n);
    }
    rep(i,n){
        rep(j,n){
            M[i][j] = (1<<21);
        }
    }

    rep(i,n){
        cin >> u >> k;
        rep(j,k){
            cin >> v;
            cin >> M[u][v];
        }
    }
    dijkstra(n,M);
    return 0;
}

C++: //#include "stdc++.h"
#include <iostream>
#include <vector>
#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <queue>
//#include "my_gettime.hpp"
//#include "my_random.hpp"
//#include "my_util.hpp"
//using namespace std;

struct Edge{
	Edge(int f, int s, int w){first = f; second = s; weight = w;};
	int first;
	int second;
	int weight;
};

struct NodeP{
	NodeP(){};
	NodeP(int i, int p, int w){id = i; prev = p; weight = w;}
	int id;
	int prev;
	int weight;
	bool operator<(const NodeP & inRhs) const{ return weight < inRhs.weight; }
	bool operator>(const NodeP & inRhs) const{ return weight > inRhs.weight; }
};

#define INF (1<<30)
class Graph{
public:
	Graph(int numnodes);
	//~Graph();
	void addEdge(Edge a);
	void addEdge_nonDirect(Edge e);
	std::vector<NodeP> dijkstra(int start);
	int numNodes;
	//Edge *adj;
	std::vector < std::vector<Edge> > adj;
};
Graph::Graph(int n){
	numNodes = n;
	//adj = (Edge *)malloc(sizeof(Edge)*n*n);
	adj.resize(n);
}
void Graph::addEdge(Edge e){
	//adj[ e.first * numNodes + e.second ] = e;
	adj[e.first].push_back(e);
}
void Graph::addEdge_nonDirect(Edge e){
	adj[e.first].push_back(e);
	Edge e2 = e;
	e2.first = e.second;
	e2.second = e.first;
	adj[e2.first].push_back(e2);
}
std::vector<NodeP> Graph::dijkstra(int start){
	//using P = pair<int , int>;
	int *cost = (int *)malloc(sizeof(int)*numNodes);
	char *flag = (char *)malloc(sizeof(char)*numNodes);
	for(int i=0;i<numNodes;i++) flag[i] = 0;
	for(int i=0;i<numNodes;i++) cost[i] = INF;
	cost[start]=0;
	std::priority_queue < NodeP ,std::vector<NodeP>, std::greater<NodeP> > Q;
	Q.push(NodeP(start,-1, 0));
	std::vector <NodeP> nodeps(numNodes);

	while( !Q.empty() ){
		NodeP node = Q.top();
		Q.pop();
		if( flag[node.id] == 1 ) continue;
		flag[node.id] = 1;
		cost[node.id] = node.weight;

		nodeps[node.id] = node;

		typedef std::vector<Edge>::iterator ITR;
		for( ITR itr = adj[node.id].begin(); itr !=adj[node.id].end(); itr++ ){
			int dis = node.weight + itr->weight;
			if( cost[itr->second] > dis ){
				Q.push(NodeP(itr->second, node.id, dis));
			}
		}

	}

	free(cost);
	free(flag);

	return nodeps;
}

int main(int argc ,char **argv){
	using namespace std;

	int numNodes;
	cin >> numNodes;

	Graph g(numNodes);

	for(int i=0;i<numNodes;i++){
		int nodeid, numedge;
		cin >> nodeid >> numedge;
		for(int j=0;j<numedge;j++){
			int target, weight;
			cin >> target >> weight;
		//	cout<< nodeid<<" "<<target<<" "<<weight<<endl;
			g.addEdge(Edge(nodeid,target,weight));
		}
	}
	vector<NodeP> nodeps = g.dijkstra(0);
	typedef std::vector<NodeP>::iterator ITR;
	for( ITR itr = nodeps.begin(); itr !=nodeps.end(); itr++ ){
		printf("%d %d\n",/*itr->prev,*/itr->id,itr->weight);
	}
	return 0;
}