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()

	list := make([][]int, n)
	weight := make([]int, n)
	for i := range list {
		list[i] = make([]int, n)
		weight[i] = NIL
		for j := range list[i] {
			list[i][j] = NIL
		}
	}

	for i := 0; i < n; i++ {
		u := scanInt()
		k := scanInt()
		for j := 0; j < k; j++ {
			v := scanInt()
			w := scanInt()
			list[u][v] = w
		}
	}

	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 i, w := range list[node.id] {
			if w == NIL {
				continue
			}
			heap.Push(h, Node{id: i, weight: w + node.weight})
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		fmt.Fprint(w, i)
		fmt.Fprint(w, " ")
		fmt.Fprint(w, weight[i])
		fmt.Fprintln(w)
	}
	w.Flush()
}

C++: #include<iostream>
#include<vector>
#include<climits>
using namespace std;

struct Edge {int to, cost;};

typedef vector<Edge> Edges;
typedef vector<Edges> Graph;

int mind(vector<int> &a,vector<int> &b){
	int n=a.size();
	int min=INT_MAX;
	int ind=0;
	for (int i=0;i<n;i++){
		if((min>a[i])&&(b[i]==0)){
			min=a[i];
			ind=i;
		}
	}
	if(min==INT_MAX){
		return -1;
	}else{
		return ind;
	}
}

int min(vector<int> &a){
	int n=a.size();
	int min=a[0];
	int ind=0;
	for (int i=0;i<n;i++){
		if(min>a[i]){
			min=a[i];
			ind=i;
		}
	}
	return min;
}

void dijkstra(Graph &G,vector<int> &d,int n,int s){
	fill(d.begin(),d.end(),INT_MAX);
	vector<int> c(n,0);
	int t;
	
	d[s]=0;
	
	while((t=mind(d,c))!=-1){
		c[t]=1;
		for(int i=0;i<G[t].size();i++){
			Edge e=G[t][i];
			if(d[e.to] > d[t]+e.cost){
				d[e.to] = d[t]+e.cost;
			}
		}
	}
}

int main(){
	int n,i,j,k;
	vector<int> d(n);
	Edge e;
	
	cin >> n;
	
	Graph G(n);
	
	for (i=0;i<n;i++){
		cin >> k >> k;
		for (j=0;j<k;j++){
			cin >> e.to >> e.cost;
			G[i].push_back(e);
		}
	}
	
	dijkstra(G,d,n,0);
	
	for (i=0;i<n;i++){
		cout << i << " " << d[i] << endl;
	}
	
	return 0;
}