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++: #define _GLIBCXX_DEBUG
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define ALL(v) v.begin(), v.end()
typedef long long ll;

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

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

#define AMAX 10010
#define INF 1001001001

int d[AMAX],color[AMAX];
vector<pair<int,int>> M[AMAX];
int n;

void dijk(int s){
  
  rep(i,n){
    d[i]=INF;
    color[i]=0;
  }
  d[s]=0;
  
  priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> p;
  p.push({0,s});
  
  pair<int,int> u;
  while(!p.empty()){
    u=p.top(); p.pop();
    color[u.second]=2;
    
    for(auto v:M[u.second]){
      if(color[v.first]!=2){
        if(d[u.second]+v.second<d[v.first]){
          d[v.first]=d[u.second]+v.second;
          color[v.first]=1;
          p.push({d[v.first],v.first});
        }
      }
    }
  }

}

int main(){
  cin>>n;
  
  int u,k,v,c;
  rep(i,n){
    cin>>u>>k;
    rep(j,k){
      cin>>v>>c;
      M[u].push_back({v,c});
    }
  }
  
  dijk(0);
  
  rep(i,n) cout<<i<<" "<<d[i]<<endl;
      
  return 0;
}

C++: #include <iostream>
#include <limits.h>
#include <vector>
#include <queue>

using namespace std;

struct Node {
    int id;
    int cost;
    bool done;
    vector<int> next_node;
    vector<int> len_cost;

    bool operator<(const Node& right) const {
        return cost > right.cost;
    }
} node[100];

int main() {
    int n, id, k;

    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> id >> k;
        node[id].id = id;
        node[id].cost = INT_MAX;
        node[id].done = false;
        node[id].next_node.resize(k);
        node[id].len_cost.resize(k);
        for (int j = 0; j < k; j++) {
            cin >> node[id].next_node[j] >> node[id].len_cost[j];
        }
    }

    priority_queue<Node> q;
    node[0].cost = 0;
    q.push(node[0]);
    while (!q.empty()) {
        Node temp = q.top();
        q.pop();

        if (temp.done == true) {
            continue;
        }
        node[temp.id].done = true;

        for (int i = 0; i < temp.next_node.size(); i++) {
            int to = temp.next_node[i];
            int cost = temp.cost + temp.len_cost[i];
            if (node[to].cost > cost) {
                node[to].cost = cost;
                if (node[to].done == false) {
                    q.push(node[to]);
                }
            }
        }
    }

    for (int i = 0; i < n; i++) {
        cout << i << " " << node[i].cost << endl;
    }
    
    return 0;
}

C++: #include <iostream>
#include <vector>
#include<algorithm>
#include <string>
#include <set>
#include <limits.h>
#include <map>
#include <queue>
#include <stack>

using namespace std;

#define rip(i,n,s) for (int i=(s);i<(int)(n);i++)
#define all(a) (a).begin(),(a).end()
typedef long long ll;
typedef pair<long long, int> P;

void dijk(vector<vector<P> > &da, int s, vector<ll> &ans) {
	priority_queue<P,vector<P>,greater<P> > q;
	int x = da[s].size();
	rip(i, x, 0) {
		q.push(da[s][i]);
	}
	ans[s] = 0;
	while (!q.empty()) {
		P no = q.top();
		q.pop();
		//printf("%lld %d\n", no.first, no.second);
		if (ans[no.second] < 0) {
			x = no.second;
			ans[x] = no.first;
			int size = da[x].size();
			rip(i, size, 0) {
				P PA = make_pair(da[x][i].first + no.first, da[x][i].second);
				q.push(PA);
			}
		}
	}
}

int main() {
    int n;
    cin >> n;
    vector<vector<P> >  da(n,vector<P>(0));
    rip(i,n,0){
        int x;
        cin >> x;
        cin >> x;
        int v,c;
        rip(j,x,0){
            cin >> v >> c;
            da[i].push_back(make_pair(c,v));
        }
    }
    vector<ll> ans(n,-1);
    dijk(da,0,ans);
    rip(i,n,0){
        printf("%d %lld\n",i,ans[i]);
    }
}

C++: #include<iostream>
#include<stdio.h>
#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 BLACK=2;
static const int GRAY=1;

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

void diks(){
    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));
        }
    }
    diks();
    return 0;
}