Go: package main

import (
	"fmt"
	"bufio"
	"os"
	"strconv"
	"container/heap"
)

type Node struct {
	Id int
	Dis int
}

type PriorityQueue []*Node

func (pq PriorityQueue) Len() int { return len(pq) }

func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].Dis < pq[j].Dis
}

func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
}

func (pq *PriorityQueue) Push(x interface{}) {
	*pq = append(*pq, x.(*Node))
}

func (pq *PriorityQueue) Pop() interface{} {
	n := len(*pq)
	pop := (*pq)[n-1]
	*pq = (*pq)[0:n-1]
	return pop
}

func main() {
	var n int
	fmt.Scan(&n)

	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	g := make([][]int, n)
	c := make([][]int, n)
	pq := make(PriorityQueue, 0, n)
	d := make([]int, n)
	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())
		g[u] = make([]int, k)
		c[u] = make([]int, k)
		for j := 0; j < k; j++ {
			sc.Scan()
			g[u][j], _ = strconv.Atoi(sc.Text())
			sc.Scan()
			c[u][j], _ = strconv.Atoi(sc.Text())
		}

		if u == 0 {
			d[u] = 0
		} else {
			d[u] = 1 << 30
		}
		pq.Push(&Node{u, d[u]})
	}
	heap.Init(&pq)

	for pq.Len() > 0 {
		node := heap.Pop(&pq).(*Node)
		for i := 0; i < len(g[node.Id]); i++ {
			nextId := g[node.Id][i]
			nextDis := node.Dis + c[node.Id][i]
			if nextDis < d[nextId] {
				d[nextId] = nextDis
				heap.Push(&pq, &Node{nextId, nextDis})
			}
		}
	}

	wr := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		wr.WriteString(strconv.Itoa(i))
		wr.WriteString(" ")
		wr.WriteString(strconv.Itoa(d[i]))
		wr.WriteString("\n")
	}
	wr.Flush()
}

C++: #include<iostream>
#include<queue>
#include<vector>
#define INF (int)1e9 + 7
using namespace std;
int n;
vector<pair<int, int> > adj[10000];
void dijkstra();
int main() {
    cin >> n;
    for (int i = 0; i < n; i++) {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            int v, c; //vertex cost
            cin >> v >> c;
            adj[u].push_back(make_pair(c, v));
        }
    }
    dijkstra();
    return 0;
}
void dijkstra() {
    int dist[n];
    dist[0] = 0;
    for (int i = 1; i < n; i++) {
        dist[i] = INF;
    }
    priority_queue<pair<int, int> > q;
    q.push(make_pair(0, 0));
    while (!q.empty()) {
        int u = q.top().second;
        int co = -q.top().first;
        q.pop();
        for (int i = 0; i < adj[u].size(); i++) {
            int v = adj[u][i].second;
            int co2 = adj[u][i].first;
            if (dist[u] + co2 < dist[v]) {
                dist[v] = co2 + dist[u];
                q.push(make_pair(-dist[v] ,v));
            }
        }
    }
    for (int i = 0; i < n; i++) {
        cout << i << " " << dist[i] << endl;
    }
    
}

C++: #include <iostream>
#include "algorithm"
#include "queue"
using namespace std;
static const int mx=10007;
static const int inf=(1<<21);

int n;
vector<pair<int, int> >adj[mx];//加权有向图的邻接表表示法

void dijkstra()
{
	priority_queue<pair<int,int> >pq;
	int d[mx],color[mx];
	
	for (int i=0;i<n;i++) {
		d[i]=inf;
		color[i]=0;
	}
	
	d[0]=0;
	color[0]=1;
	pq.push(make_pair(0,0));
	while (!pq.empty()) {
		pair<int , int>f=pq.top();pq.pop();
		int u=f.second;
		
		color[u]=2;
		
		//取出最小值，如果不是最短路径则忽略。	
		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]==2)continue;
			if(d[v]>d[u]+adj[u][j].second)
			{
				d[v]=d[u]+adj[u][j].second;
				///priority_queue默认优先较大值，因此要乘以-1；
				pq.push(make_pair(d[v]*(-1), v));
				color[v]=1;
			}
		}
	}
		for (int i=0;i<n;i++) 
			cout<<i<<" "<<(d[i]==inf?-1:d[i])<<endl;
}
int main(int argc, char *argv[]) {
	
	int k,c,u,v;
	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) < (n);(i)++)
#define SORT(c) sort((c).begin(),(c).end())
#define MOD 1000000007
using namespace std;
typedef long long ll;

const int MAX = 10005;
const int WHITE = 0;
const int GRAY = 1;
const int BLACK = 2;

int n;
vector<pair<int, int>> adj[10005];

void dijkstra(){

  priority_queue<pair<int,int>,
                  vector<pair<int, int>>,
                  greater<pair<int, int>>> PQ;
  int color[10005];
  int d[10005];
  rep(i, n){
    d[i] = MOD;
    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;

    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], v));
        color[v] = GRAY;
      }
    }
  }
  rep(i, n){
    cout << i << " " << (d[i] == MOD ? -1 : d[i]) << endl;
  }
}

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

  dijkstra();

  return 0;
}

C++: #include <iostream>
#include <queue>
#include <algorithm>
#include <vector>
#include <climits>
#define int long long
using namespace std;
typedef pair <int,int> P;
#define to first
#define co second
#define fi first
#define se second
const int INF=INT_MAX;
const int MAX_V=100000;
vector <P> G[MAX_V];
int v,d[MAX_V];
void dijk(int s){
  priority_queue <P,vector<P>,greater<P> > que;
  fill(d,d+v,INF);
  d[s]=0;
  que.push(P(0,s));
  for(;!que.empty();){
    P p=que.top(); que.pop();
    int v=p.se;
    if (d[v]<p.fi) continue;
    for(int i=0;i<(int)G[v].size();i++){
      P e=G[v][i];
      if(d[e.to]>d[v]+e.co){
	d[e.to]=d[v]+e.co;
	que.push(P(d[e.to],e.to));
      }
    }
  }
}
signed main(){

  cin>>v;
  for(int i=0,u,k;i<v&&cin>>u>>k;i++) for(int j=0,a,b;j<k&&cin>>a>>b;j++) G[u].push_back(P(a,b));
  dijk(0);
  for(int i=0;i<v;i++) cout<<i<<" "<<d[i]<<endl;
  return 0;

}

C++: #include <bits/stdc++.h>
using namespace std;
typedef unsigned long long ull;
typedef long long ll;

map <int,int> mp;

#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};

typedef pair<int, int> P; //最短距離,頂点の番号
struct edge{
    int to,cost;
};
int N;
vector<edge> G[MAX]; //
int d[MAX]; //最短距離

void dijkstra(int s){
    priority_queue<P, vector<P>,greater<P> > que;
    
    fill(d,d+N,INF);
    d[s]=0;
    que.push(P(0,s));
    
    while(!que.empty()){
        P p=que.top(); que.pop();
        int v=p.second;
        
        if(d[v] < p.first) continue;
        for(int i=0;i<G[v].size();i++){
            edge e=G[v][i];
            if(d[e.to]>d[v]+e.cost){
                d[e.to] =d[v]+e.cost;
                que.push(P(d[e.to],e.to));
            }
        }
    }
}


int main(){
    cin.tie(0);  ios::sync_with_stdio(false);
    
    int k,u;
    cin>>N;
    for(int i=0;i<N;i++){
        cin>>u>>k;
        for(int j=0;j<k;j++){
            edge e;
            cin>>e.to>>e.cost;
            G[u].push_back(e);
        }
    }
    dijkstra(0);
    for(int i=0;i<N;i++)
        cout<<i<<" "<<(d[i]==INF?-1:d[i])<<"\n";
    
    return 0;
    }