Go: package main

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

//make priority queue
type Item struct {
	id       int
	priority int // this state is priority and distans from start
	index    int
}

type PriorityQueue []*Item

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

// we want the ascending-priority-queue.
// So we use less than here.
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 = j
	pq[j].index = i
}

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
}

func (pq *PriorityQueue) update(dist int, id int) {
	for _, i := range *pq {
		if i.id == id {
			if i.priority > dist {
				i.priority = dist
			}
		}
	}
}

// the main code
func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())
	return n
}

func dikstra(dist [][]int, n int) []int {
	// preparate priority queue
	inf := 1 << 30
	pq := make(PriorityQueue, n)
	shortests := make([]int, n)
	for i := 0; i < n; i++ {
		pq[i] = &Item{
			id:       i,
			priority: inf,
			index:    i,
		}

		shortests[i] = inf
	}
	pq[0].priority = 0
	shortests[0] = 0

	for pq.Len() > 0 {
		item := heap.Pop(&pq).(*Item)
		shortests[item.id] = item.priority
		for id, d := range dist[item.id] {
			if d != -1 {
				pq.update(item.priority+d, id)
			}
		}
		heap.Init(&pq)
	}
	return shortests
}

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

	// init
	n := nextInt(sc)
	dist := make([][]int, n)
	for i := 0; i < n; i++ {
		dist[i] = make([]int, n)
		for j := 0; j < n; j++ {
			dist[i][j] = -1
		}
	}

	// std Input
	for i := 0; i < n; i++ {
		u := nextInt(sc)
		k := nextInt(sc)
		for j := 0; j < k; j++ {
			v, c := nextInt(sc), nextInt(sc)
			dist[u][v] = c
		}
	}

	shortests := dikstra(dist, n)
	for i, d := range shortests {
		fmt.Printf("%d %d\n", i, d)
	}
}

C++: #include<bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vs = vector<string>;
using msi = map<string, int>;
using mii = map<int, int>;
using psi = pair<string, int>;
using pii = pair<int, int>;
using vlai = valarray<int>;
#define rep(i,n) for(int i=0;i<n;i++)
#define range(i,s,n) for(int i=s;i<n;i++)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define fs first
#define sc second
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define INF 1E9
#define EPS 1E-9
#define MOD (ll)(1E9+7)
#define PI 3.1415926535897932384

template <class T>ostream &operator<<(std::ostream &o, const vector<T> &v)
{
	rep(i, v.size()) {
		o << (i > 0 ? " " : "") << v[i];
	}
	return o;
}

#define MAX_V 100

struct edge {
	edge(int a, int b) {
		cost = a;
		to = b;
	}
	int cost;
	int to;
};

int n;
vector<vector<edge>> G;
vector<int> d;

void dijkstra(int s) {
	priority_queue<pii, vector<pii>, greater<pii>> que;
	d[s] = 0;
	que.push(pii(0, s));

	while (!que.empty()) {
		pii 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(pii(d[e.to], e.to));
			}
		}
	}

}

int main() {
	int n,u,k,tmpp,tmpw;
	cin >> n;
	d = vector<int>(n, INF);
	G = vector<vector<edge>>(n);
	rep (i,n) {
		cin >> u >> k;
		rep(j, k) {
			cin >> tmpp>>tmpw;
			G[u].emplace_back(tmpw, tmpp);
		}
	}
	dijkstra(0);
	rep(i, n) {
		cout << i << " " << d[i] << endl;
	}
}

C++: #define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;

#define rep(i, n) REP(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define MSG(a) cout << #a << " " << a << endl;
#define REP(i, x, n) for (int i = x; i < n; i++)
#define OP(m) cout << m << endl
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> P;

int main()
{
    int n;
    cin >> n;
    vector<P> m[n];

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

    priority_queue<P, vector<P>, greater<P>> pq;
    int d[n];
    rep(i, n) d[i] = INT_MAX;
    d[0] = 0;
    pq.push(make_pair(0, 0));
    while (!pq.empty())
    {
        P p = pq.top();
        pq.pop();
        int u = p.second;
        if (d[u] < p.first)
            continue;
        rep(j, m[u].size())
        {
            int v = m[u][j].first;
            if (d[v] > d[u] + m[u][j].second)
            {
                d[v] = d[u] + m[u][j].second;
                pq.push(make_pair(d[v], v));
            }
        }
    }

    rep(i, n)
    {
        cout << i << " " << d[i] << endl;
    }

    return 0;
}

C++: #include <cstdio>
#include <cstring>
#include <climits>
#include <vector>
#include <map>
using namespace std;

typedef vector<int>::iterator vitr;
typedef map<int, int>::iterator mitr;

map<int, int> w[100];
int d[100];

vector<int> others;

void findPath(){
    int candiW = INT_MAX;
    vitr candiI;
    for(vitr i=others.begin();i!=others.end();i++){
        if(d[*i] < candiW){
            candiI = i;
            candiW = d[*i];
        }
    }

    for(mitr i=w[*candiI].begin();i!=w[*candiI].end();i++){
        if(d[*candiI] + i->second < d[i->first]){
            d[i->first] = d[*candiI] + i->second;
        }
    }

    others.erase(candiI);
}

int main(){
    int i,j,u,k,n,v,c;


    scanf("%d",&n);
    for(i=0;i<n;i++){
        scanf("%d %d",&u,&k);
        for(j=0;j<k;j++){
            scanf("%d %d",&v,&c);
            w[u][v] = c;
        }
    }

    for(i=0;i<n;i++)d[i]=INT_MAX;
    d[0] = 0;
    for(i=0;i<n;i++)others.push_back(i);
    for(i=0;i<n;i++)findPath();
    for(i=0;i<n;i++)printf("%d %d\n",i,d[i]);

    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 d[MAX],color[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,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>
using namespace std;
#define M 10000
#define  INF 1<<20
int n;
vector<pair<int,int > > a[M];
void dijkstra(){
	priority_queue<pair<int,int> > Q;
	bool col[M];
	int d[M];
	for(int i=0;i<n;i++){
		col[i]=0;
		d[i]=INF;
	}
	d[0]=0;
	Q.push(make_pair(0,0));
	while(!Q.empty()){
		pair<int,int>f=Q.top();Q.pop();
		int u=f.second;col[u]=1;
		if(d[u]<f.first*(-1))continue;
		for(int j=0;j<a[u].size();j++){
			int v=a[u][j].first;
			if(col[v])continue;
			if(d[v]>d[u]+a[u][j].second){
				d[v]=d[u]+a[u][j].second;
				Q.push(make_pair(d[v]*(-1),v));
			}
		}
	}
	for(int i=0;i<n;i++)cout<<i<<' '<<(d[i]==INF?-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;
			a[u].push_back(make_pair(v,c));
		}
	}
	dijkstra();
}