Go: package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
	"strconv"
)

const NIL = -1

type Node struct {
	id     int
	weight int
}

func init() {
	sc.Split(bufio.ScanWords)
}

type NodeHeap []Node

func (h NodeHeap) Len() int           { return len(h) }
func (h NodeHeap) Less(i, j int) bool { return h[i].weight < h[j].weight }
func (h NodeHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *NodeHeap) Push(x interface{}) {
	*h = append(*h, x.(Node))
}

func (h *NodeHeap) Pop() interface{} {
	old := *h
	n := len(old)
	x := old[n-1]
	*h = old[0 : n-1]
	return x
}

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func main() {
	n := scanInt()

	route := make([][]Node, n)
	weight := make([]int, n)
	for i := 0; i < n; i++ {
		weight[i] = NIL
	}

	for i := 0; i < n; i++ {
		u := scanInt()
		k := scanInt()
		route[i] = make([]Node, k)
		for j := 0; j < k; j++ {
			route[u][j] = Node{id: scanInt(), weight: scanInt()}
		}
	}

	start := Node{id: 0, weight: 0}
	h := &NodeHeap{start}
	heap.Init(h)

	for h.Len() > 0 {
		node := heap.Pop(h).(Node)
		if weight[node.id] != NIL {
			continue
		}
		weight[node.id] = node.weight

		for _, nextNode := range route[node.id] {
			if weight[nextNode.id] != NIL {
				continue
			}
			nextNode.weight += node.weight
			heap.Push(h, nextNode)
		}
	}

	for i, w := range weight {
		fmt.Println(i, w)
	}
}

C++: #include<iostream>
#include<string>
#include<algorithm>
#include<queue>
#include<vector>
#include<stack>
using namespace std;
#define MAX 100
#define WHITE 0
#define GRAY 1
#define BLACK 2
#define INFTY (1<<30)
int n;
vector<pair<int,int> > adj[MAX];

void dijkstra()
{
  priority_queue<pair<int,int> > PQ;
  int d[MAX],color[MAX];
  for(int i=0;i<n;i++)
    {
      d[i]=INFTY;
      color[i]=WHITE;
    }
  d[0] = 0;
  PQ.push(make_pair(0,0));
  color[0]=GRAY;
  while(!PQ.empty())
    {
      pair<int,int> f= PQ.top(); PQ.pop();
      int u=f.second;
      color[u]=BLACK;
      if(d[u] < f.first * (-1) ) continue;
      for(int j=0;j<adj[u].size();j++)
	{
	  int v=adj[u][j].first;
	  if(color[v] == BLACK) continue;
	  if(d[v] > d[u] + adj[u][j].second)
	    {
	      d[v]=d[u]+adj[u][j].second;
	      PQ.push(make_pair(d[v] *(-1), v));
	      color[v]=GRAY;
	    }
	}
    }
  for( int i=0;i<n;i++)
    {
      cout << i << " " << (d[i]==INFTY ? -1: d[i] ) << endl;
    }
}

int main(){
  cin >> n;

  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;
	  adj[u].push_back(make_pair(v,c));
	}
    }
  dijkstra();
  return 0;
}

C++: #include<stdio.h>
#include<iostream>
#include<algorithm>
#include<string>
#include<string.h>
#include<math.h>
#include<stdlib.h>
#include<vector>
#include<queue>
#include<map>
#define rep(index,num) for(int index=0;index<num;index++)
#define rep1(index,num) for(int index=1;index<=num;index++)
#define scan(argument) cin>>argument
#define prin(argument) cout<<argument<<endl
#define kaigyo cout<<endl
#define eps 1e-15
#define mp(a1,a2) make_pair(a1,a2)
typedef long long ll;
using namespace std;
typedef pair<int,int> pint;
typedef vector<int> vint;
typedef vector<pint> vpint;
int INF=1e+9+1;
int N;
vpint adj[10000];
int d[100],color[100],p[100];
void dijkstra(){
	priority_queue<pint> PQ;
	rep(i,N){
		d[i]=INF;
		color[i]=0;
	}
	d[0]=0;
	color[0]=1;
	PQ.push(mp(0,0));
	while(!PQ.empty()){
		pint f=PQ.top();
		PQ.pop();
		int u=f.second;
		color[u]=2;
		if(d[u]< -f.first) continue;
		rep(j,adj[u].size()){
			int v=adj[u][j].first;
			if(color[v]==2) continue;
			if(d[v]>d[u]+adj[u][j].second){
				d[v]=d[u]+adj[u][j].second;
				PQ.push(mp(-d[v],v));
				color[v]=1;
			}
		}
	}
}
int main(){
	scan(N);
	int k,c,u,v;
	rep(i,N){
		scan(u);scan(k);
		rep(j,k){
			scan(v);scan(c);
			adj[u].push_back(mp(v,c));
		}
	}
	dijkstra();
	rep(i,N){
		printf("%d %d\n",i,(d[i]==INF ? -1 : d[i]));
	}
	return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <queue>
using namespace std;
static const int MAX = 10000;
static const int INFTY (1<<20);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<pair<int, int> > adj[MAX];

void dijkstra() {
  priority_queue<pair<int, int> > PQ;
  int color[MAX];
  int d[MAX];
  for ( int i = 0; i < n; i++ ) {
    d[i] = INFTY;
    color[i] = WHITE;
  }

  d[0] = 0;
  PQ.push(make_pair(0,0));
  color[0] = GRAY;

  while ( !PQ.empty()) {
    pair<int, int> f = PQ.top(); PQ.pop();
    int u = f.second;

    color[u] = BLACK;

    if ( d[u] < f.first * (-1)) continue;

    for ( int j = 0; j < adj[u].size(); j++) {
      int v = adj[u][j].first;
      if ( color[v] == BLACK ) continue;
      if ( d[v] > d[u] + adj[u][j].second) {
	d[v] = d[u] + adj[u][j].second;
	PQ.push(make_pair(d[v] * (-1), v));
	color[v] = GRAY;
      }
    }
  }

  for ( int i = 0; i < n; i++) {
    cout << i << " " << ( d[i] == INFTY ? -1 : d[i] ) << endl;
  }
}

int main() {
  int k, u, v, c;

  cin >> n;
  for ( int i = 0; i < n; i++ ) {
    cin >> u >> k;
    for ( int j = 0; j < k; j++) {
      cin >> v >> c;
      adj[u].push_back(make_pair(v, c));
    }
  }

  dijkstra();

  return 0;
}

C++: #define _CRT_SECURE_NO_WARNINGS
#include<iostream>
#include<cstdio>
#include<string>
#include<algorithm>
#include<cmath>
#include<vector>
#include<queue>
using namespace std;

#define REP(i,n) for(int i=0;(i)<(n);(i)++)

static const int MAX = 10000;
static const int INFTY = (1 << 20);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<pair<int, int>> adj[MAX];

void dijkstra() {
	priority_queue<pair<int, int>> PQ;
	int color[MAX];
	int dist[MAX];
	REP(i, n) {
		dist[i] = INFTY;
		color[i] = WHITE;
	}

	dist[0] = 0;
	PQ.push(make_pair(0, 0));
	color[0] = GRAY;

	while (!PQ.empty()) {
		pair<int, int> f = PQ.top(); PQ.pop();
		int u = f.second;
		color[u] = BLACK;

		//????°???????????????????????????????????????§???????????°??????
		if (dist[u] < f.first*(-1)) continue;

		REP(j, adj[u].size()) {
			int v = adj[u][j].first;
			if (color[v] == BLACK) continue;
			if (dist[v] > dist[u] + adj[u][j].second) {
				dist[v] = dist[u] + adj[u][j].second;
				PQ.push(make_pair(dist[v] * (-1), v));
				color[v] = GRAY;
			}
		}
	}

	REP(i, n) {
		cout << i << " " << (dist[i] == INFTY ? -1 : dist[i]) << endl;
	}
}

int main() {
	int k, u, v, c;
	cin >> n;
	REP(i, n) {
		cin >> u >> k;
		REP(j, k) {
			cin >> v >> c;
			adj[u].push_back(make_pair(v, c));
		}
	}

	dijkstra();

	return 0;
}