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 <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;
}

C++: // -*- mode:c++; coding:utf-8; c-basic-offset:2; -*-
// ALDS1_12_C: Single Source Shortest Path II

#include <algorithm>
#include <cstdio>
#include <queue>
#include <utility>
#include <vector>

using uint = unsigned int;

class Graph {
  using vc_t = std::pair<uint, uint>;
  std::vector<std::vector<vc_t>> g_;

public:
  Graph(const uint n) { g_.resize(n); }

  void push_to(const uint u, const uint v, const uint c)
  {
    g_[u].push_back(std::make_pair(v, c));
  }

  void dijkstra(uint* dist)
  {
    auto n = g_.size();
    const uint INFINIT = 100000*(n-1)+1;
    std::fill_n(dist, n, INFINIT);
    auto cmp = [](vc_t left, vc_t right) { return left.second > right.second; };
    std::priority_queue<vc_t, std::vector<vc_t>, decltype(cmp)> q(cmp);
    
    q.push(vc_t(0, 0));
    dist[0] = 0u;
    while (!q.empty()) {
      auto bvc = q.top();
      q.pop();
      auto v = bvc.first;
      auto c = bvc.second;
      if (dist[v] < c) {
        continue;
      }
      dist[v] = c;
      for (auto vc : g_[v]) {
        q.push(std::make_pair(vc.first, vc.second+c));
      }
    }
  }
};

int main()
{
  uint n;
  std::scanf("%u", &n);

  Graph g(n);

  uint u, k, v, c;
  for (auto i = 0u; i < n; ++i) {
    std::scanf("%u %u", &u, &k);
    for (auto j = 0u; j < k; ++j) {
      std::scanf("%u %u", &v, &c);
      g.push_to(u, v, c);
    }
  }

  uint dist[n];
  g.dijkstra(dist);
  for (auto i = 0u; i < n; ++i) {
    std::printf("%u %u\n", i, dist[i]);
  }
}

// eof

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<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[v] + 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;
}