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;
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 <vector>
#include <queue>
using namespace std;
#define INF 1e9
typedef pair<int, int> pi;
int used[10100];
int dist[10100];

int main() {
  int n;
  cin >> n;
  
  // first:weight, second:key
  priority_queue<pi, vector<pi>, greater<pi>> pqueue;
  // graph[from][to], first:key, second:distance
  vector<vector<pi>> graph(n);
  
  for (int i = 0; i < n; i++) {
    dist[i] = INF;
  }
  for (int i = 0; i < n; i++) {
    int u, k;
    cin >> u >> k;
    vector<pi> vec(k);
    int v, c;
    for (int j = 0; j < k; j++) {
      cin >> v >> c;
      vec[j] = make_pair(v, c);
    }
    graph[i] = vec;
  }

  pqueue.push(make_pair(0,0));
  dist[0] = 0;
  
  for (int i = 0; i < n; i++) {
    pi p = pqueue.top();
    pqueue.pop();
    int key = p.second;
    if (used[key] == 1) {
      i--;
      continue;
    }
    dist[key] = min(dist[key], p.first);
    used[key] = 1;
    for (int j = 0; j < graph[key].size(); j++) {
      if (used[graph[key][j].first] != 1) {
        int d = graph[key][j].second + dist[key];
        pqueue.push(make_pair(d, graph[key][j].first));
      }
    }
  }

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

C++: #include <iostream>
#include<cstdlib>
#include<queue>
#include<set>
#include<vector>
#include<string>
#include<algorithm>
#include<stack>
#include<map>
#include<cstdio>
#include<fstream>
using namespace std;
#define rep(i,a) for(int i=0;i<a;i++)

#define mp make_pair
#define P pair<int,int>
#define ll __int64
vector<P>G[20000];
int n,u,k;
const int INF=100000000;
int ans[20000];

int main(){
	int from,cost;
	cin>>n;

	rep(i,n){
		cin>>u>>k;
		rep(i,k){
				cin>>from>>cost;
				G[u].push_back(mp(from,cost));
		}
	}
	rep(i,n)ans[i]=INF;
	//ans[0]=0;
	priority_queue<P,vector<P>,greater<P> >que;//firstスタートからの重みsecond頂点
	que.push(mp(0,0));
	
	while(!que.empty()){
		P now=que.top();
		que.pop();
		if(ans[now.second]!=INF)continue;
		int index=now.second;
		ans[index]=now.first;
		//cout<<now.first<<endl;
		for(int i=0;i<G[now.second].size();i++)que.push(mp(now.first+G[index][i].second,G[index][i].first));//次への経路長、頂点番号
	}
	for(int i=0;i<n;i++)cout<<i<<" "<<ans[i]<<endl;
	return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <queue>

using namespace std;

static const int MAX = 10000;
static const int INF = 1 << 30;
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 d[MAX], color[MAX];

    for (int i = 0; i < n; ++i){
        d[i] = INF;
        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] == INF ? -1 : d[i]) << endl;
    }
}

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