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 _CRT_SECURE_NO_WARNINGS
#include<iostream>
#include<cstdio>
#include<string>
#include<algorithm>
#include<cmath>
#include<vector>
#include<queue>
using namespace std;

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

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 dist[MAX];
	REP(i, n) {
		dist[i] = INFTY;
		color[i] = WHITE;
	}

	dist[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 (dist[u] < f.first*(-1)) continue;

		REP(j, adj[u].size()) {
			int v = adj[u][j].first;
			if (color[v] == BLACK) continue;
			if (dist[v] > dist[u] + adj[u][j].second) {
				dist[v] = dist[u] + adj[u][j].second;
				PQ.push(make_pair(dist[v] * (-1), v));
				color[v] = GRAY;
			}
		}
	}

	REP(i, n) {
		cout << i << " " << (dist[i] == INFTY ? -1 : dist[i]) << endl;
	}
}

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

	dijkstra();

	return 0;
}

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

#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define repi(i,a,b) for(int i = (a); i < (b); i++)

using namespace std;

typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;

const int INF=1<<29;
const double EPS=1e-9;

const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};
const int MAX_N =10010;
int d[MAX_N];//最短距離
struct edge{
	int from,to,cost;
	edge(int _from,int _to,int _cost){
		from =_from;
		to =_to;
		cost =_cost;
	}
};
vector<edge> es;//辺
int V,E;//頂点数と変数

void bellman(int s){
	for(int i =0;i <V;i++)d[i]=INF;
	d[s] = 0;
	while(true){
		bool update=false;
		for(int i =0;i <E;i++){
			edge e =es[i];
			if(d[e.from]!=INF&&d[e.to] >d[e.from] +e.cost){
				d[e.to] =d[e.from]+e.cost;
				update =true;
			}
		}
		if(!update)break;
	}
}
int main(){
	cin>>V;
	E = 0;
	for(int i =0;i < V;i++){
		int node,k;
		cin>>node>>k;
		for(int j =0;j <k;j++){
			int x,c;
			cin>>x>>c;
			es.push_back(edge(node,x,c));
			E++;
		}
	}
	bellman(0);
	for(int i=0;i < V;i++){
		cout <<i<<" "<<d[i]<<endl;
	}
	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[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 <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(ri,n) for(int ri = (int)(n-1); ri >= 0; ri--)
#define rep2(i,x,n) for(int i = (int)(x); i < (int)(n); i++)
#define repit(itr,x) for(auto itr = x.begin(); itr != x.end(); itr++)
#define rrepit(ritr,x) for(auto ritr = x.rbegin(); ritr != x.rend(); ritr++)
#define ALL(n) begin(n), end(n)
using ll = long long;
using namespace std;

const int INF = 1001001001;

int main(){
  int n;
  cin >> n;
  vector<vector<pair<int, int>>> gr(n, vector<pair<int, int>>());
  rep(i, n){
    int a;
    cin >> a;
    int k;
    cin >> k;
    rep(j, k){
      int v, c;
      cin >> v >> c;
      gr.at(i).push_back(make_pair(v, c));
    }
  }
  vector<bool> chk(n, false);
  vector<int> d(n, INF);
  priority_queue<pair<int, int>> q;
  q.push(make_pair(0, 0));
  int co = 0;
  while(!q.empty()){
    auto now = q.top(); q.pop();
    if(chk.at(now.second) == true) continue;
    d.at(now.second) = -1 * now.first;
    chk.at(now.second) = true;
    co++;
    if(co == n) break;

    for(auto p : gr.at(now.second)){
      if(chk.at(p.first) == true) continue;
      q.push(make_pair(now.first-p.second, p.first));
    }
  }

  rep(i, n){
    cout << i << " " << d.at(i) << endl;
  }
  return 0;
}