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 <bits/stdc++.h>
using namespace std;
typedef unsigned long long ull;
typedef long long ll;
typedef pair<int, int> P;
map <int,int> mp;
vector<int> V;
#define INF (1<<30)
#define INFLL (1ll<<60)
#define EPS (1e-10)
static const int MAX=1e5;
static const int MOD=1e9+7;
static const int NMAX=50;
static const int MMAX=50;
int dx[4]={0,1,0,-1},dy[4]={-1,0,1,0};
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int N;
int d[MAX];
vector<P> adj[MAX]; //<隣接地点,その地点の最短距離>
void dijkstra(int s){
    priority_queue<P> PQ; //<最短距離*-1,場所>
    int color[MAX];
    for(int i=0;i<N;i++){
        d[i]=INF;
        color[i]=WHITE;
    }
    
    d[s]=0;
    PQ.push(make_pair(0,0));
    color[0]=GRAY;
    
    while(!PQ.empty()){
        P f=PQ.top(); PQ.pop();
        int u=f.second; //次に行く場所の候補
        
        color[u]=BLACK;
        
        if(d[u]<f.first*(-1)) continue; //候補の今の時点の最短距離が、記録されてるのより小さい
        
        for(int j=0;j<adj[u].size();j++){
            int v=adj[u][j].first; //uのj番目の隣接地点のインデックス
            if(color[v]==BLACK) continue; //もう行った
            if(d[v]<=d[u]+adj[u][j].second)continue;//vにはもっと早い行き方がある
            d[v]=d[u]+adj[u][j].second;
            PQ.push(make_pair(d[v]*(-1),v));
            color[v]=GRAY;
        }
        
    }
}


int main(){
    cin.tie(0);  ios::sync_with_stdio(false);
    
    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(0);
    for(int i=0;i<N;i++)
        cout<<i<<" "<<(d[i]==INF?-1:d[i])<<"\n";
    
    return 0;
}

C++: #include <bits/stdc++.h>

using weight = int;

struct edge {
    int to;
    weight cost;
};

using edges = std::vector<edge>;
using graph = std::vector<edges>;

// when g has neg cycle, second -> false
std::pair<std::vector<weight>, bool> spfa(graph const& g, int s) {
    constexpr weight inf = std::numeric_limits<weight>::max() / 2;
    const int n = g.size();
    std::vector<weight> d(n, inf);
    std::vector<int> in_q(n), count(n);
    std::queue<int> que;
    d[s] = 0;
    que.emplace(s);
    in_q[s] = true;
    ++count[s];
    bool neg_cycle = false;
    [&]() {
        while(!que.empty()) {
            int v = que.front();
            que.pop();
            in_q[v] = false;
            for(auto& e : g[v]) {
                if(d[v] != inf && d[e.to] > d[v] + e.cost) {
                    d[e.to] = d[v] + e.cost;
                    if(!in_q[e.to]) {
                        que.emplace(e.to);
                        in_q[e.to] = true;
                        ++count[e.to];
                        if(count[e.to] >= n) {
                            neg_cycle = true;
                            return;
                        }
                    }
                }
            }
        }
    }();

    return std::make_pair(d, !neg_cycle);
}

using namespace std;

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[u].push_back(edge{v, c});
        }
    }

    auto ans = spfa(g, 0).first;
    for(int i = 0; i < n; ++i) {
        cout << i << ' ' << ans[i] << endl;
    }
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <queue>
using namespace std;
const int maxx=10010;
const int infinity=1<<30;

int main() {
	int n,a,b,c,e;
	vector<pair<int, int> > A[maxx];
	bool flag[maxx];
	int d[maxx];
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>a>>b;
		for(int j=0;j<b;j++){
			cin>>c>>e;
			A[a].push_back(make_pair(c,e));
		}
	}
	for(int i=0;i<n;i++){
		flag[i]=false;
		d[i]=infinity;
	}
	priority_queue<pair<int,int> > PQ;
	d[0]=0;
	PQ.push(make_pair(0, 0));
	while(PQ.empty()==0){
		pair<int, int> u=PQ.top();
		PQ.pop();
		//cout<<u.first<<" "<<d[u.first]<<endl;
		flag[u.second]=true;
		int len=A[u.second].size();
		for(int i=0;i<len;i++){
			int v=A[u.second][i].first;
			if(flag[v]==false && d[u.second]+A[u.second][i].second<d[v]){
				d[v]=d[u.second]+A[u.second][i].second;
				PQ.push(make_pair(d[v]*(-1),v));
			}
		}
	}

	for(int i=0;i<n;i++) cout<<i<<" "<<(d[i]==infinity ? -1 : d[i])<<endl;

	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n) ; i++)
constexpr auto INF = 2147483647;
typedef long long ll;

static const int MAX = 10000;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

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

void dijkstra(){
  priority_queue<pair<int,int>> pq;
  int color[MAX], d[MAX];
  rep(i,n){
    color[i] = WHITE;
    d[i] = INF;
  }
  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_vec[u].size(); j++){
      int v = Adj_vec[u][j].first;
      if(color[v] == BLACK) continue;
      if(d[v] > d[u] + Adj_vec[u][j].second){
        d[v] = d[u] + Adj_vec[u][j].second;
        pq.push(make_pair(d[v] * -1, v));
        color[v] = GRAY;
      }
    }
  }
  rep(i,n){
    cout << i << " " << (d[i] == INF ? -1 : d[i]) << endl;
  }
}

int main(){
  int k, c, u, v;
  cin >> n;
  rep(i,n){
    cin >> u >> k;
    rep(j,k){
      cin >> v >> c;
      Adj_vec[u].push_back(make_pair(v, c));
    }
  }

  dijkstra();

  return 0;
}