Go: package main

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

//make priority queue
type Item struct {
	id       int
	priority int // this state is priority and distans from start
	index    int
}

type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }

// we want the ascending-priority-queue.
// So we use less than here.
func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].priority < pq[j].priority
}

func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = j
	pq[j].index = i
}

func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}

func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	item.index = -1 //for safety
	*pq = old[0 : n-1]
	return item
}

func (pq *PriorityQueue) update(dist int, id int) {
	for _, i := range *pq {
		if i.id == id {
			if i.priority > dist {
				i.priority = dist
			}
		}
	}
}

// the main code
func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())
	return n
}

func dikstra(dist [][]int, n int) []int {
	// preparate priority queue
	inf := 1 << 30
	pq := make(PriorityQueue, n)
	shortests := make([]int, n)
	for i := 0; i < n; i++ {
		pq[i] = &Item{
			id:       i,
			priority: inf,
			index:    i,
		}

		shortests[i] = inf
	}
	pq[0].priority = 0
	shortests[0] = 0

	for pq.Len() > 0 {
		item := heap.Pop(&pq).(*Item)
		shortests[item.id] = item.priority
		for id, d := range dist[item.id] {
			if d != -1 {
				pq.update(item.priority+d, id)
			}
		}
		heap.Init(&pq)
	}
	return shortests
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	// init
	n := nextInt(sc)
	dist := make([][]int, n)
	for i := 0; i < n; i++ {
		dist[i] = make([]int, n)
		for j := 0; j < n; j++ {
			dist[i][j] = -1
		}
	}

	// std Input
	for i := 0; i < n; i++ {
		u := nextInt(sc)
		k := nextInt(sc)
		for j := 0; j < k; j++ {
			v, c := nextInt(sc), nextInt(sc)
			dist[u][v] = c
		}
	}

	shortests := dikstra(dist, n)
	for i, d := range shortests {
		fmt.Printf("%d %d\n", i, d)
	}
}

C++: #define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
using namespace std;

const int NOTV = 0;
const int VIST = 1;
const int NMAX = 10000;
//const int VMAX = 2000;
const int NILL = -1;
const int INF = 1 << 21;
//int a[NMAX][NMAX];  //??£??\??????
int n;
vector<pair<int, int> > adj[NMAX];

void dijkstra() {
	int d[NMAX];
	int vst[NMAX];
	priority_queue<pair<int, int> > pq;
	for (int i = 0; i < n; i++) {
		vst[i] = NOTV;
		d[i] = INF;
	}
	d[0] = 0;
	pq.push(make_pair(d[0], 0));
	while (not pq.empty()) {
		pair<int, int> f = pq.top(); pq.pop();
		int u = f.second;
		vst[u] = VIST;
		if (d[u] < f.first*(-1)) continue;
		for (int i = 0; i < adj[u].size(); i++) {
			int v = adj[u][i].first;
			if (vst[v] == NOTV) {
				if (d[u] + adj[u][i].second < d[v]) {
					d[v] = d[u] + adj[u][i].second;
					pq.push(make_pair(d[v] * (-1), v));
				}
			}
		}
	}
	for (int i = 0; i < n; i++) {
		cout << i << ' ' << d[i] << endl;
	}
}

int main() {
	cin >> n;
	int k, u, v, c;
	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++: //
//  main.cpp
//
//
//  Created by ???????????? on 2017/10/23.
//  Copyright ?? 2017 ????????????. All rights reserved.
//

#include <iostream>
#include <stdio.h>
#include <queue>
#include <algorithm>


#define n_max 10000
#define WHITE 0
#define GRAY 1
#define BLACK 2
#define INFTY 1<<20

using namespace std;

int n, color[n_max], d[n_max], p[n_max];

vector<pair<int, int> > adj[n_max];


void init(){
    int i, j, id, num, node, weight;
    scanf("%d", &n);
    
    for(i = 0; i < n; i++){
        scanf("%d %d", &id, &num);
        for(j = 0; j < num; j++){
            scanf("%d", &node);
            scanf("%d", &weight);
            adj[id].push_back(make_pair(node, weight));
        }
        color[i] = WHITE;
        d[i] = INFTY;
    }
}

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

int main(int argc, const char * argv[]) {
    init();
    dijkstra();
    return 0;
}

C++: #include <iostream>
#include <sstream>
#include <cstdio>
#include <cmath>
#include <cctype>
#include <string>
#include <vector>
#include <list>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <algorithm>
#include <functional>

using namespace std;
using ll = long long int;
#define rep(i,n) for(int i = 0; i < n; i++)
#define FOR(i, a, b)  for(int i = (a); i < (b) ; i++)

#define pb push_back
#define SORT(v,n) sort(v, v+n)
#define ALL(x) (x).begin(),(x).end()
#define debug(x) cerr << #x << ": " << x << '\n'
#define elif else if
#define itn ll
#define int ll
const int INF = 100100100;
const int MOD = (int)1e9 + 7;
const double EPS = 1e-9;
///                →,↑,←,↓,↗,↖,↙,↘
int dx[8] = { 1, 0, -1, 0, 1, -1, -1, 1 };
int dy[8] = { 0, 1, 0, -1, 1, 1, -1, -1 };
typedef vector<vector<int>> vvi;
typedef vector<vector<vector<int>>> vvvi;
int i, j, k;

static const int MAX = 10000;
static const int White = 0;
static const int Gray = 1;
static const int Black = 2;

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

void dijkstra() {
	int d[MAX],  color[MAX];
	rep(i, n) {
		d[i] = INF;
		color[i] = White;
	}
	priority_queue<pair<int, int>> PQ;
	PQ.push(make_pair(0, 0));
	d[0] = 0;
	color[0] = Gray;
	while (!PQ.empty()) {
		pair<int,int> f = PQ.top();
		PQ.pop();
		int u = f.second;
		color[u] = Black;
		rep(i, adj[u].size()) {
			pair<int,int> x = adj[u][i];
			int v = x.first;
			int c = x.second;
			if (color[v] == Black) continue;
			if (d[v] < d[u] + c) continue;
				d[v] = d[u] + x.second;
				PQ.push(make_pair(d[v] * -1, v));
				color[v] = Gray;
		}
	}
	rep(i, n) {
		cout << i << ' ' << (d[i] == INF ? -1 : d[i]) << '\n';
	}
}

signed main() {
	ios::sync_with_stdio(false);
	cin >> n;
	rep(i, n) {
		int u,k;
		cin >> u >> k;
		rep(j, k) {
			int v, c;
			cin >> v >> c;
			adj[u].pb(make_pair(v, c));
		}
	}
	dijkstra();
	return 0;
}