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 <cstdio>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
// N 为邻接矩阵的大小
#define N 10001
#define WHITE 0
#define GRAY 1
#define BLACK 2
#define INFTY 1 << 21

using namespace std;

int color[N], d[N], p[N];
vector<pair<int, int> > adj[N];

void dijkstra (int s, int n) {
  priority_queue<pair<int, int> > PQ;

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

  d[s] = 0;
  p[s] = -1;
  PQ.push(make_pair(0, 0));
  color[0] = GRAY;

  while (PQ.size()) {
    pair<int, int> f = PQ.top();
    PQ.pop();
    int u = f.second;

    color[u] = BLACK;

    // 取出最小值，如果不是最短路径就忽略
    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 && d[u] + adj[u][j].second < d[v]) {
        d[v] = d[u] + adj[u][j].second;
        p[v] = u;
        // 优先队列默认优先较大值，因此要乘以 -1
        PQ.push(make_pair(d[v] * (-1), v));
        color[v] = GRAY;
      }
    }
  }
}

int main () {
  int n, u, v, degree, cost;
  
  cin >> n;

  for (int i = 0; i < n; i++) {
    cin >> u >> degree;
    
    for (int j = 0; j < degree; j++) {
      cin >> v >> cost;
      
      adj[i].push_back(make_pair(v, cost));
    }
  }

  dijkstra(0, n);

  for (int i = 0; i < n; i++)
    cout << i << " " << d[i] << endl;

  return 0;
}

C++: #include <iostream>
#include <vector>
#include <queue>
static const int MAX = 10000;
static const int INFTY = (1<<20);
static const int WHITE = 0;
static const int BLACK = 1;

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

void dijkstra() {
  std::priority_queue<std::pair<int, int> > PQ;
  int color[MAX];
  int d[MAX];
  for(int i=0; i<n; ++i) {
    color[i] = WHITE;
    d[i] = INFTY;
  }

  d[0] = 0;
  PQ.push(std::make_pair(0, 0));

  while(!PQ.empty()) {
    std::pair<int, int> f = PQ.top();
    PQ.pop();
    int u = f.second; // ..? これは重みでは?

    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(std::make_pair(d[v] * (-1), v));
      }
    }
  }

  for(int i=0; i<n; ++i) {
    std::cout << i << " " << d[i] << std::endl;
  }

}


int main() {
  int k, u, v, c;
  std::cin >> n;

  for(int i=0; i<n; ++i) {
    std::cin >> u >> k;
    for(int j=0; j<k; ++j) {
      std::cin >> v >> c;
      adj[u].push_back(std::make_pair(v, c));
    }
  }

  dijkstra();
}

C++: #include<iostream>
#include<iomanip>
#include<algorithm>
#include<bitset>
#include<cctype>
#include<cmath>
#include<cstdio>
#include<cstring>
#include<functional>
#include<limits>
#include<list>
#include<map>
#include<set>
#include<stack>
#include<string>
#include<sstream>
#include<queue>
#include<vector>
using namespace std;

#define MOD 1000000007
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3fLL

#define MAX 10000
#define WHITE 0
#define GRAY 1
#define BLACK 2

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

typedef pair<int, int> pii;

void dijkstra() {
	priority_queue<pii, vector<pii>, greater<pii> >PQ; //d[id] d
	int color[MAX] = {},
		d[MAX];
	fill(d, d + MAX, INF);
	d[0] = 0;

	//?§????????????\
	PQ.push(make_pair(0, 0));
	color[0] = GRAY;

	//PQ???????´????????????°
	while (!PQ.empty()) {
		//d????????§???(-????°????)??¨??????????´????????????????
		pii f = PQ.top(); PQ.pop();

		int u = f.second;
		color[u] = BLACK;

		//????????§???????????°??????
		if (d[u] < f.first) { 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], v));
				color[v] = GRAY;
			}
		}
	}
	for (int i = 0; i < n; i++) {
		cout << i << " " << (d[i] == INF ? -1 : d[i]) << endl;
	}
}

int main() {
	cin >> 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;
			adj[u].push_back(make_pair(v, c));
		}
	}
	dijkstra();
	return 0;
}