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>
#define INF 1e9
#define MAX_V 100
using namespace std;
int cost[MAX_V][MAX_V];
int d[MAX_V];
bool used[MAX_V];
int V;
void dijkstra(int s){
    fill(d,d+V,INF);
    fill(used,used+V,false);
    d[s]=0;
    
    while(true){
        int v=-1;
        for(int u=0;u<V;u++){
            if(!used[u] && (v == -1 || d[u] < d[v])){
                v = u;
            }
        }
        
        if(v == -1) break;
        
        used[v] = true;
        
        for(int u=0;u<V;u++){
            d[u] = min(d[u],d[v]+cost[v][u]);
        }
    }
    
    for(int i=0;i<V;i++) cout<<i<<" "<<d[i]<<endl;

    return ;
}

int main(){
    cin>>V;
    int u,k,v,c;

    for(int i=0;i<V;i++)
        for(int j=0;j<V;j++) cost[i][j]=INF;
    
    for(int i=0;i<V;i++){
        cin>>u>>k;
        for(int j=0;j<k;j++){
            cin>>v>>c;
            cost[u][v]=c;
        }
    }
    
    dijkstra(0);
    
    return 0;
}

C++: #include<iostream>
#include<iomanip>
#include<queue>
#include<string>
#include<stack>
#include<cstdio>
#include<cstdlib>
#include<cmath>
#include<cstring>
#include<cassert>
#include<ctime>
#include<algorithm>
#include<utility>
#include<map>
#include<set>
#include<vector>
#include<functional>

using namespace std;

#ifdef DEBUG
#define dprintf      printf
#define dout(x)      cout<<#x" = "<<(x)<<endl
#define darray(x,n)    {int i;rep(i,n)cout<<#x"["<<i<<"] = "<<*((x)+i)<<endl;}
#define dloop(i,s,g) for((i)=(s);(i)<(g);(i)++)
#define drep(i,n)    for((i)=0;(i)<(n);(i)++)
#define dstop()      scanf("%*c")
#else
#define dprintf      (1)?0:printf
#define dout(x)
#define darray(x,n)
#define dloop(i,s,g) if(1){}else
#define drep(i,n)    if(1){}else
#define dstop()      if(1){}else
#endif

#define F    first
#define S    second
#define pb   push_back
#define mp   make_pair

#define loop(i,s,g) for((i)=(s);(i)<(g);(i)++)
#define rep(i,n)    for((i)=0;(i)<(n);(i)++)
#define all(x)      (x.begin(),x.end())
#define in(T,...) T __VA_ARGS__; impl(__VA_ARGS__);
#define array(T,id,n) T id[n]; rep(i,n)cin>>id[i];

//#define int long long;
#ifndef int
#define INF  (0x7fffffff)
#else
#define LINF (0x7fffffffffffffff)
#endif

typedef long long           ll;
typedef unsigned            ui;
typedef unsigned long long  ull;
typedef pair<int,int>       i_i;
typedef pair<ll,int>        ll_i;
typedef pair<ll,ll>         ll_ll;
typedef pair<double,int>    d_i;
typedef pair<double,double> d_d;

void impl(){};
template <typename T,typename... TS >
void impl(T &head,TS &... tail)
{
  cin>>head;
  impl(tail ...);
}

typedef struct edge
{
  int to;
  int cost;
}Edge;
int V;
#define MAX_V (1000)
vector<Edge> G[MAX_V];
int d[MAX_V];

void djikstra(int s)
{
  int i;
  priority_queue<i_i,vector<i_i>,greater<i_i> > q;
  fill(d,d+V,INF);
  d[s]=0;
  q.push(i_i(0,s));
  while(!q.empty())
    {
      i_i p=q.top();
      q.pop();
      int v=p.S;
      if(d[v]<p.F)
	continue;
      rep(i,G[v].size())
	{
	  Edge e=G[v][i];
	  if(d[e.to]>d[v]+e.cost)
	    {
	      d[e.to]=d[v]+e.cost;
	      q.push(i_i(d[e.to],e.to));
	    }
	}
    }
}

signed main(void)
{
  int n;
  int i,j;
  int u;
  int k;
  Edge e;

  cin>>n;
  rep(i,n)
    {
      cin>>u>>k;
      rep(j,k)
	{ 
	  cin>>e.to>>e.cost;
	  G[j].pb(e);
	}
    }
  djikstra(0);
  rep(i,n)
    {
      cout<<i<<" "<<d[i]<<endl;
    }
  return 0;
}

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 << " " << ( 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>
#define INF (1<<21)
#define WHITE 1
#define BLACK 2
#define GRAY 3
#define neg -1
using namespace std;

int n;
int m[100][100];
vector<int> g;
vector<int> color;

void di(){
  int u, mincost;

  for(int i = 0; i < n; i++){
    g[i] = INF;
    color[i] = WHITE;
  }

  g[0] = 0;
  color[0] = GRAY;

  while(1){
    mincost = INF;
    u = -1;

    for(int i = 0; i < n; i++){
      if(mincost > g[i] && color[i] != BLACK){
	u = i;
	mincost = g[i];
      }
    }

    if(u == neg) break;

    color[u] = BLACK;

    for(int i = 0; i < n; i++){
      if(color[i] != BLACK && m[u][i] != INF){
	if(g[i] > (g[u] + m[u][i])){
	  g[i] = g[u] + m[u][i];
	  color[i] = GRAY;
	}
      }
    }
  }

  for(int i = 0; i < n; i++){
    cout << i << " " << (g[i] == INF ? neg:g[i]) << endl;

  }
}

int main()
{
  cin >> n;
  g.resize(n);
  color.resize(n);

  for(int i = 0; i < n; i++){
    for(int j = 0; j < n; j++){
      m[i][j] = INF;
    }
  }

  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;
    }
  }

  di();

  return 0;

}