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 <stdio.h>
#include <vector>
#include <algorithm>


using namespace std;

short heap_index[10000];

struct Info{
	Info(){
		to=0;
		weight = 0;
	}
	Info(short arg_to,int arg_weight){
		to = arg_to;
		weight = arg_weight;
	}
	short to;
	int weight;
};

class InfoPQ{
public:
	InfoPQ(){
		array = new Info[10000];
		n = 0;
	}
	void push(Info arg_info){
		array[n] = arg_info;
		int tmp = n;
		while(tmp != 0 && array[tmp].weight < array[(tmp-1)/2].weight){
			std::swap(array[tmp], array[(tmp-1)/2]);
			tmp = (tmp-1)/2;
		}
		n++;
	}

	bool isEmpty(){
		return n == 0;
	}

	void writeHeapIndex(){
		for(int i=0;i<n;i++){
			heap_index[array[i].to] = i;
		}
	}

	void update(short update_index,int new_weight){
		array[heap_index[update_index]].weight = new_weight;
		int tmp = heap_index[update_index];
		while(tmp != 0 && array[tmp].weight < array[(tmp-1)/2].weight){
			std::swap(heap_index[array[tmp].to],heap_index[array[(tmp-1)/2].to]);
			std::swap(array[tmp], array[(tmp-1)/2]);
			tmp = (tmp-1)/2;
		}
	}

	Info pop(){
		Info ret = array[0];
		n--;
		heap_index[array[n].to] = 0;
		std::swap(array[0],array[n]);
		int tmp = 0;
		while(2*tmp+1 <= n-1){
			if(2*tmp+2 <= n-1){
				if(array[2*tmp+2].weight < array[tmp].weight && array[2*tmp+2].weight <= array[2*tmp+1].weight){
					std::swap(heap_index[array[tmp].to],heap_index[array[2*tmp+2].to]);
					std::swap(array[2*tmp+2],array[tmp]);
					tmp = 2*tmp+2;
				}else if(array[2*tmp+1].weight < array[tmp].weight && array[2*tmp+1].weight <= array[2*tmp+2].weight){
					std::swap(heap_index[array[tmp].to],heap_index[array[2*tmp+1].to]);
					std::swap(array[2*tmp+1],array[tmp]);
					tmp = 2*tmp+1;
				}else{
					break;
				}
			}else{
				if(array[tmp].weight > array[2*tmp+1].weight){
					std::swap(heap_index[array[tmp].to],heap_index[array[2*tmp+1].to]);
					std::swap(array[tmp],array[2*tmp+1]);
					tmp = 2*tmp+1;
				}else{
					break;
				}
			}
		}
		return ret;
	}

private:
	Info* array;
	int n;
};



int main(){
	int n,count=0,tmp,left_node,right_node,dist;
	short size;
	scanf("%d",&n);
	vector<Info> V[n];
	Info catcher;
	InfoPQ A;

	int P[n],zero_dist[n];

	for(int i=0;i<n;i++){
		P[i]=0;
		zero_dist[i] = 10000001;
	}
	zero_dist[0] = 0;
	P[0]=1;

	for(int i=0;i<n;i++){
		scanf("%d %d",&left_node,&tmp);
		if(left_node == 0){
			for(int k=0;k<tmp;k++){
				scanf("%d %d",&right_node,&dist);
				zero_dist[right_node] = dist;
			}
		}else{
			for(int k=0;k<tmp;k++){
				scanf("%d %d",&right_node,&dist);
				V[left_node].push_back(Info(right_node,dist));
			}
		}
	}

	for(short k=1;k<n;k++){
		A.push(Info(k,zero_dist[k]));
	}

	A.writeHeapIndex();

	while(count<n-1){

		catcher = A.pop();
		P[catcher.to]=1;
		count++;
		size = V[catcher.to].size();
		for(int k=0;k<size;k++){
			if(zero_dist[V[catcher.to][k].to] > catcher.weight+V[catcher.to][k].weight){
				zero_dist[V[catcher.to][k].to] = catcher.weight+V[catcher.to][k].weight;
				A.update(V[catcher.to][k].to,catcher.weight+V[catcher.to][k].weight);
			}
		}
	}

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

    return 0;
}

C++: #include <iostream>
#include <iomanip>
#include <vector>
#include <set>
#include <string>
#include <queue>
#include <algorithm>
#include <map>
#include <cmath>
#include <list>
#include <stack>
#include <cstdio>
#include <cstdlib>
#include <cstring>

#define rep(i, n) for (int i = 0; i < n; i++)

using namespace std;
typedef vector<int> vi;
typedef pair<int, int> pii;

const int INF = 1 << 30;
const long long INFL = 1LL << 60;
const int MOD = 1000000007;
const int MAX = 100000;
const int N = 10000;

vector<pii> G[N];
long long d[N];

int main() {
	int n; cin >> n;
	rep(i, n) {
		int _, n2; cin >> _ >> n2;
		rep(j, n2) {
			int v, c; cin >> v >> c;
			G[i].push_back(pii(c, v));
		}
	}
	rep(i, n) d[i] = INFL;

	priority_queue<pii, vector<pii>, greater<pii>> Q;
	d[0] = 0;
	Q.push(pii(0, 0));
	while (!Q.empty()) {
		pii p = Q.top(); Q.pop();
		for (auto i : G[p.second]) {
			if (d[i.second] <= d[p.second] + i.first) continue;
			d[i.second] = d[p.second] + i.first;
			Q.push(i);
		}
	}
	rep(i, n) cout << i << ' ' << d[i] << endl;
}

C++: ///
// File:  alds1_12_c.cpp
// Author: ymiyamoto
//
// Created on Wed Oct 18 22:36:29 2017
//

#include <cstdint>
#include <iostream>
#include <queue>
#include <vector>

using namespace std;

#define SIZE 10000

struct route_t {
  uint32_t node;
  int64_t weight;

  bool operator<(const route_t &r) const
  {
    return weight > r.weight;
  }
};

static vector<route_t> graph[SIZE];
static int64_t costs[SIZE];
static bool visited[SIZE];
static priority_queue<route_t> q;

static void dikstra()
{
  q.push({0, 0});
  costs[0] = 0;

  while (!q.empty()) {
    route_t r = q.top();
    q.pop();

    if (!visited[r.node]) {
      visited[r.node] = true;
      for (uint32_t i = 0; i < graph[r.node].size(); i++) {
        int64_t cost = graph[r.node][i].weight;
        uint32_t node = graph[r.node][i].node;
        if (cost != -1) {
          if (costs[r.node] + cost < costs[node]) {
            costs[node] = costs[r.node] + cost;
            q.push({node, costs[node]});
          }
        }
      }
    }
  }
}

int32_t main()
{
  uint32_t n;
  cin >> n;

  for (uint32_t i = 0; i < n; i++) {
    costs[i] = INT32_MAX;
  }

  for (uint32_t i = 0; i < n; i++) {
    uint32_t id, k;
    cin >> id >> k;
    for (uint32_t j = 0; j < k; j++) {
      route_t r;
      cin >> r.node >> r.weight;
      graph[id].push_back(r);
    }
  }

  dikstra();

  for (uint32_t i = 0; i < n; i++) {
    cout << i << " " << costs[i] << endl;
  }

  return 0;
}