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 <cstring>
#include <vector>
#include <queue>
#include <functional>
using namespace std;

const int Max = 10005;
const int INF = (1<<29);
struct Node
{
    int v, c;
    bool operator < (const Node& a) const{
        return c > a.c;
    }
};

int n, color[Max], d[Max], p[Max];
int u, k, v, c;
vector<Node> G[Max];
priority_queue<Node> pq;
Node pn;

void dijstra()
{
    memset(color, -1, sizeof(color));
    for(int i=0; i<n; i++)
    {
        d[i] = INF;
    }
    d[0] = 0;
    p[0] = -1;
    pn = {0, d[0]};
    pq.push(pn);

    while(!pq.empty())
    {
        pn = pq.top(); pq.pop();
        int u = pn.v;
        color[u] = 0;
     
        for(int j=0; j<G[u].size(); j++)
        {
            int v = G[u][j].v;
            if(color[v]!=0 && d[u]+G[u][j].c<d[v])
            {
                d[v] = G[u][j].c+d[u];
                pn = {v, d[v]};
                pq.push(pn);
                p[j] = u;//j的父节点为u，有利于重建MST
            }
        }
    }
    //打印输出
    for(int i=0; i<n; i++)
    {
        if(d[i]==INF)
            cout << i << " " << -1 << endl;
        else
            cout << i << " " << d[i] << endl;
    }
}

int main()
{
    cin >> n;
    for(int i=0; i<n; i++)
    {
         cin >> u >> k;
         for(int i=0; i<k; i++)
         {
             cin >> v >> c;
             Node pn = {v, c};
             G[u].push_back(pn);
         }
    }

    dijstra();
    return 0;
}

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

const int INFY = numeric_limits<int>().max();
typedef pair<int, int> pa;

class graph {
public:
    graph(int n): n_(n), adj_(n) {
    }
    void add(int u, int v, int weight) {
        adj_[u].push_back(pa(weight, v));
    }
    vector<int> dijkstra(int start) {
        vector<int> d(n_, INFY);
        vector<bool> visited(n_, false);
        priority_queue<pa, vector<pa>, greater<pa>> q;
        d[0] = 0;
        q.push(pa(0, start));
        while(!q.empty()) {
            int uw = q.top().first;
            int u = q.top().second;
            q.pop();
            visited[u] = true;
            if (d[u] < uw) continue;
            for (auto pav : adj_[u]) {
                int v = pav.second;
                int w = pav.first;
                if (visited[v]) continue;
                if(d[u] + w < d[v]) {
                    d[v] = d[u] + w;
                    q.push(pa(d[v], v));
                }
            }
        }
        return d;
    }
private:
    int n_;
    vector<vector<pa>> adj_;
};


int main() {
    int n;
    cin >> n;
    graph g(n);
    for (int i = 0; i < n; ++i) {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; ++j) {
            int v, c;
            cin >> v >> c;
            g.add(u, v, c);
        }
    }
    auto d = g.dijkstra(0);
    for (int i = 0; i < n; ++i) {
        cout << i << " " << (d[i] == INFY ? -1 : d[i]) << endl;
    }
}

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;
}