Go: package main

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

type Item struct {
	value    int // The value of the item; arbitrary.
	priority int // The priority of the item in the queue.
	// The index is needed by update and is maintained by the heap.Interface methods.
	index int // The index of the item in the heap.
}
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }
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 = i
	pq[j].index = j
}
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
}

type Q struct {
	pq *PriorityQueue
	ds map[int]int // It has always same value as pq. For random access.
}

func newQ() *Q {
	pq := new(PriorityQueue)
	heap.Init(pq)
	return &Q{
		pq: pq,
		ds: make(map[int]int),
	}
}
func (q *Q) pop() (u, d int) {
	item := heap.Pop(q.pq).(*Item)
	delete(q.ds, item.value)
	return item.value, item.priority
}
func (q *Q) get(u int) (int, bool) { // returns d
	d, ok := q.ds[u]
	return d, ok
}
func (q *Q) set(u, d int) {
	q.ds[u] = d
	for _, item := range *q.pq {
		if item.value != u {
			continue
		}

		item.priority = d
		heap.Fix(q.pq, item.index)
		return
	}
	heap.Push(q.pq, &Item{
		priority: d,
		value:    u,
	})
}
func (q *Q) len() int {
	return len(q.ds)
}

func main() {
	r := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(r, &n)
	cs := make([]map[int]int, n) // []v_i -> c_i
	for h := 0; h < n; h++ {
		var u, k int
		fmt.Fscan(r, &u, &k)
		m := make(map[int]int)
		for i := 0; i < k; i++ {
			var v, c int
			fmt.Fscan(r, &v, &c)
			m[v] = c
		}

		cs[u] = m
	}

	q := newQ()
	q.set(0, 0)
	visited := make(map[int]struct{})
	out := make([]int, n)

	for q.len() > 0 {
		u, d := q.pop()
		for uu, c := range cs[u] {
			// Consider the connection between u and uu.
			if _, ok := visited[uu]; ok {
				continue
			}
			dd := d + c
			if d, ok := q.get(uu); !ok || d > dd {
				q.set(uu, dd)
			}
		}

		out[u] = d
		visited[u] = struct{}{}
	}

	for u, d := range out {
		fmt.Println(u, d)
	}
}

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;
}

C++: #include<cstdio>
#include<vector>
#include<algorithm>
#include<utility>
#include<numeric>
#include<iostream>
#include<array>
#include<string>
#include<sstream>
#include<stack>
#include<queue>
#include<list>
#include<functional>
#define _USE_MATH_DEFINES

#include<math.h>
#include<map>

#define SENTINEL 1000000001

#define min(a,b) (a)>(b)?(b):(a)
#define max(a,b) (a)>(b)?(a):(b)

using namespace std;

typedef pair<int, int> pii;

struct Edge
{
	int t, c;
	Edge(int t,int c):t(t),c(c){}
};

vector<Edge> edges[10000];
int d[10000];

void dijkstra(int n)
{
	priority_queue<pii, vector<pii>, greater<pii>> pq;
	d[0] = 0;
	pq.push(make_pair(0, 0));

	while (!pq.empty())
	{
		pii tp = pq.top();
		pq.pop();

		if (d[tp.second] < tp.first)
		{
			continue;
		}

		for (int i = 0; i != edges[tp.second].size(); i++)
		{
			if (d[tp.second] + edges[tp.second][i].c < d[edges[tp.second][i].t])
			{
				d[edges[tp.second][i].t] = d[tp.second] + edges[tp.second][i].c;
				pq.push(make_pair(d[edges[tp.second][i].t], edges[tp.second][i].t));
			}
		}
	}
}

int main()
{
	int n;
	cin >> n;

	for (int i = 0; i < n; i++)
	{
		d[i] = 100000000;
	}

	for (int i = 0; i < n; i++)
	{
		int id, k;
		cin >> id >> k;
		for (int j = 0; j < k; j++)
		{
			int v, c;
			cin >> v >> c;
		
			edges[id].push_back(Edge(v, c));
		}
	}

	dijkstra(n);

	for (int i = 0; i < n; i++)
	{
		printf("%d %d\n", i, d[i]);
	}

	return 0;
}