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 <bits/stdc++.h>
#define rep(i, n) for(int i = 0; i < (n); i++)
using namespace std;
using ll = long long;
using P = pair<int, int>;

constexpr int LEN = 10005;
vector<P> a[LEN];

void dikstra(const int n){
	int d[n];
	bool check[n] = {0};
	memset(d, 1, sizeof(d));
	priority_queue<P, vector<P>, greater<P> > h;

	d[0] = 0;
	h.push(make_pair(d[0], 0));
	check[0] = 1;

	while(h.size()){
		P f = h.top(); h.pop();
		int u = f.second;
		int uc = f.first;
		check[u] = 1;
		for(P vf : a[u]){
			int v = vf.second;
			int vc = vf.first;
			if(!check[v]){
				if((uc + vc) < d[v]){
					d[v] = uc + vc;
					h.push(make_pair(d[v], v));
				}
			}
		}
	}

	rep(i, n) cout << i << ' ' << d[i] << endl;
	return;
}

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

	dikstra(n);
	return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <queue>
using namespace std;

// first: cost, second: key
typedef pair<int, int> vert;

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

vector<vert> adjs[MAX];

void dijkstra(int n_v, int v_start) {
    priority_queue< vert, vector<vert>, greater<vert> > visitings;
    int color[MAX];
    int costs[MAX];

    for (int i = 0; i < n_v; i++) {
        costs[i] = INFTY;
        color[i] = WHITE;
    }

    costs[v_start] = 0;
    visitings.push( make_pair(0, v_start) );

    while (! visitings.empty()) {
        vert nearest = visitings.top();
        visitings.pop();

        int next_id = nearest.second;
        color[next_id] = BLACK;

        if ( costs[next_id] < nearest.first )
            continue;

        for (int i = 0; i < adjs[next_id].size(); i++) {
            int adj  = adjs[next_id][i].first;
            int cost = adjs[next_id][i].second;

            if (color[adj] == BLACK)
                continue;

            if (costs[next_id] + cost < costs[adj]) {
                costs[adj] = costs[next_id] + cost;
                visitings.push( make_pair(costs[adj], adj) );
            }
        }
    }

    for (int i = 0; i < n_v; i++) {
        cout << i << " " << costs[i] << "\n";
    }
}

int main() {
    std::ios::sync_with_stdio(false);

    int n_v;
    cin >> n_v;

    for (int i = 0; i < n_v; i++) {
        int vert_id, n_adjs;
        cin >> vert_id >> n_adjs;

        for (int j = 0; j < n_adjs; j++) {
            int adj, cost;
            cin >> adj >> cost;
            adjs[vert_id].push_back( make_pair(adj, cost) );
        }
    }

    dijkstra(n_v, 0);
}

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

#define INFTY (1 << 30)

//???????????????
enum Color {
	WHITE,
	GRAY,
	BLACK,
};


//SSSP
void Dijkstra(vector<pair<int, int>> *v_w_m, int verNum) {

	//???????¨????
	priority_queue<pair<int, int>> pQ;
	int distance[10000];
	Color color[10000];
	int parent[10000];
	for (int i = 0; i < verNum; i++) {
		color[i] = WHITE;
		distance[i] = INFTY;
		parent[i] = -1;
	}
	distance[0] = 0;
	pQ.push(make_pair(0, 0));


	//SSSP??????
	while (!pQ.empty()) {

		//??°??¬????????????????????????????°?????????????????????¶
//		int min_cost = INFTY;
		int subScript;
		pair<int, int> wei_sub_map = pQ.top();
		pQ.pop();
		subScript = wei_sub_map.second;
		//for (int i = 0; i < verNum; i++) {
		//	if (color[i] != BLACK && distance[i] < min_cost) {
		//		min_cost = distance[i];
		//		subScript = i;
		//	}
		//}

		//?????????????????????
		color[subScript] = BLACK;

		//???????????????????????°??????????????????????????????????????????
		//?????????????????¨4169407B?????¨??????0.01sec????????????
		if (distance[subScript] < wei_sub_map.first * -1)
			continue;

		//??£??\?????°??¬??????
		for (int i = 0; i < v_w_m[subScript].size(); i++) {
			int outV = v_w_m[subScript][i].first;
			if (color[outV] == BLACK) continue;
			if (distance[outV] < distance[subScript] + v_w_m[subScript][i].second) continue;

			distance[outV] = distance[subScript] + v_w_m[subScript][i].second;
			parent[outV] = subScript;
			color[outV] = GRAY;
			pQ.push(make_pair(distance[outV] * -1, outV));
		}
	}

	//??????
	int weight_sum = 0;
	for (int i = 0; i < verNum; i++) {
		cout << i << " " << (distance[i] == INFTY ? -1 : distance[i]) << endl;
	}
}


int main() {

	int verNum;
//	int verValWeight[100][100];
	vector<pair<int, int>> v_w_m[10000];
	int parent[10000];

	//???????¨????
//	v_w_m = new vector<pair<int, int>>();
	cin >> verNum;
	//for (int i = 0; i < verNum; i++)
	//	for (int j = 0; j < verNum; j++)
	//		verValWeight[i][j] = INFTY;

	//??\?????????
	for (int i = 0; i < verNum; i++) {
		int verVal, outNum;
		cin >> verVal >> outNum;
		for (int j = 0; j < outNum; j++) {
			int outVerVal, weight;
			cin >> outVerVal >> weight;
//			v_w_m[verVal].push_back(make_pair(outVerVal, weight));
			v_w_m[verVal].push_back(make_pair(outVerVal, weight));
			//			verValWeight[i][outVerVal] = weight;
		}
	}

	//SSSP
	Dijkstra(v_w_m, verNum);

	return 0;
}