Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
const INF = 1 << 60

type Edge struct {
	to, cost int
}

type Node struct {
	id, cost int
}

type PQ []Node

func (pq PQ) Len() int           { return len(pq) }
func (pq PQ) Less(i, j int) bool { return pq[i].cost < pq[j].cost }
func (pq PQ) Swap(i, j int)      { pq[i], pq[j] = pq[j], pq[i] }

func (pq *PQ) Push(x interface{}) {
	*pq = append(*pq, x.(Node))
}

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

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	E := make([][]Edge, N)
	for i := 0; i < N; i++ {
		id, k := sc.nextInt(), sc.nextInt()
		E[id] = make([]Edge, k)
		for j := 0; j < k; j++ {
			to, cost := sc.nextInt(), sc.nextInt()
			E[id][j] = Edge{to, cost}
		}
	}

	d := make([]int, N)
	for i := 0; i < N; i++ {
		d[i] = INF
	}
	done := make([]bool, N)
	pq := &PQ{}
	heap.Init(pq)
	d[0] = 0
	heap.Push(pq, Node{0, 0})
	for pq.Len() > 0 {
		cur := heap.Pop(pq).(Node).id
		if done[cur] {
			continue
		}
		done[cur] = true
		for i := 0; i < len(E[cur]); i++ {
			to, cost := E[cur][i].to, E[cur][i].cost+d[cur]
			if !done[to] && cost < d[to] {
				d[to] = cost
				heap.Push(pq, Node{to, cost})
			}
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i, d[i])
	}
	wtr.Flush()
}

C++: #include <iostream>
#include <set>
#include <vector>
#include <queue>
#include <stack>
#include <utility>
#include <algorithm>

using namespace std;

typedef long long signed int ll;

constexpr ll NIL = -20000000000;

class path{
public:
    int from;
    int to;
    int dist;
    path(){
        from = -1;
        to = -1;
        dist = -1;
    }
    path(int from_,int to_,int dist_){
        from = from_;
        to = to_;
        dist = dist_;
    }
    static bool compare(const path& a,const path& b) {
        return a.from < b.from;
    }
    bool operator<(const path& e) const {
        return this->dist < e.dist;
    }
};

int n,u,k,v,c;
vector<path> w;
ll d[10000];

int main() {
    for(int i = 0;i < 10000;i++)d[i] = -NIL;
    cin >> n;
    for(int i = 0;i < n;i++) {
        cin >> u >> k;
        for(int j = 0;j < k;j++) {
            cin >> v >> c;
            w.push_back(path(u,v,c));
        }
    }
    sort(w.begin(),w.end(),path::compare);
    priority_queue<pair<int,int>> q;
    q.push(make_pair(0,0));
    d[0] = 0;
    while(!q.empty()) {
        auto y = q.top();q.pop();
        if(d[y.second] != y.first) continue;
        auto r = lower_bound(w.begin(),w.end(),path(y.second,0,0),path::compare);
        auto l = lower_bound(w.begin(),w.end(),path(y.second+1,0,0),path::compare);
        for(auto itr = r;itr < l;itr++) {
            if(d[itr->to] > d[itr->from] + itr->dist) {
                d[itr->to] = d[itr->from] + itr->dist;
                q.push(make_pair(d[itr->to],itr->to));
            }
        }
    }
    for(int i = 0;i < n;i++){
        cout << i << " " << d[i] << endl;
    }
}

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

typedef pair<int, int> P;
const int M = 1000000007;

vector<int> dijkstra(int s, vector<vector<P>> edge) {
    int n = edge.size();
    vector<int> dist(n, M);
    priority_queue<P, vector<P>, greater<P>> q;
    dist[s] = 0;
    q.push(P(0, s));
    while (!q.empty()) {
        P p = q.top();
        q.pop();
        for (auto& e : edge[p.second]) {
            if (dist[e.second] > p.first + e.first) {
                dist[e.second] = p.first + e.first;
                q.push(P(p.first + e.first, e.second));
            }
        }
    }
    return dist;
}


int main() {
    int n;
    cin >> n;
    vector<vector<P>> edge(n);
    for (int i = 0; i < n; ++i) {
        int u, k;
        cin >> u >> k;
        if (i != u) exit(1);
        for (int j = 0; j < k; ++j) {
            int v, c;
            cin >> v >> c;
            edge[i].push_back(P(c, v));
        }
    }
    vector<int> d = dijkstra(0, edge);
    for (int i = 0; i < n; ++i) {
        cout << i << " " << d[i] << "\n";
    }
    return 0;
}

C++: //
//  ALDS1_12_B_SingleSortestPath.cpp
//  AizuOnlineJudge
//
//  Created by jiji on 2018/02/21.
//  Copyright © 2018年 jiji4000. All rights reserved.
//

#include <iostream>
#include <algorithm>
#include <queue>
using namespace std;
#define MAX 10000
#define INFTY 1<<22
#define WHITE 0
#define GRAY 1
#define BLACK 2

// 重み付き有向グラフの隣接リスト
vector<pair<int,int>> adj[MAX];

void dijkstra(int n){
    priority_queue<pair<int,int>>pq;
    // weight[v]に始点sからvまでの最短コストを保存する
    int weight[MAX];
    // 訪問状態を記録
    int color[MAX];
    // 1.初期化
    for(int i = 0;i < n;++i){
        weight[i] = INFTY;
        color[i] = WHITE;
    }
    
    // 始点
    weight[0] = 0;
    color[0] = GRAY;
    pq.push(make_pair(0,0));
    
    while(!pq.empty()){
        pair<int,int> first = pq.top();
        pq.pop();
        // 頂点
        int u = first.second;
        color[u] = BLACK;
        
        // 最短値を取りだして、最短でなければ飛ばす
        if(weight[u] < first.first * -1) continue;
        
        for(int i = 0;i < adj[u].size();++i){
            int v = adj[u][i].first;
            if(color[v] == BLACK)continue;
            if(weight[v] > weight[u] + adj[u][i].second){
                weight[v] = weight[u] + adj[u][i].second;
                // priority_queueはデフォルトで大きい値を優先するので-にする
                pq.push(make_pair(weight[v] * -1, v));
                color[v] = GRAY;
            }
        }
    }
    
    // 出力
    for(int i = 0;i < n;++i){
        cout << i << " " << ( weight[i] == INFTY ? -1 : weight[i] ) << endl;
    }
}

int main(){
    int n,k,c,u,v;
    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(n);
    return 0;
}