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
	heap.Init(&pq)

	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 <iostream>
#include <cstdio>
#include <cstdlib>
#include <cassert>
#include <string>
#include <cstring>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <algorithm>

using namespace std;

// ---------------------
// repetition
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)

// debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

// ---------------------
#define INF (1 << 21)
typedef long long ll;

int main() {
  int n;
  cin >> n;

  vector<int> V[n];
  // int E[n][n];
  map<pair<int, int>, int> E;
  int d[n];
  int visited[n];

  priority_queue<pair<int, int> , vector<pair<int, int> >, greater<pair<int, int> > > Q;

  REP(i, n) {
    d[i] = INF;
    visited[i] = 0;
  }

  REP(_, n) {
    int u, k;
    cin >> u >> k;
    REP(__, k) {
      int v, c;
      cin >> v >> c;
      V[u].push_back(v);
      E[make_pair(u, v)] = c;
    }
  }

  d[0] = 0;
  Q.push(make_pair(d[0], 0));
  REP(_, n) {
    // int minv = -1;
    // int mincost = INF;
    // REP(v, n) {
    //   if (!visited[v] && d[v] < mincost) {
    //     minv = v;
    //     mincost = d[v];
    //   }
    // }
    int mincost = Q.top().first;
    int minv = Q.top().second;

    visited[minv] = 1;
    for (vector<int>::iterator it = V[minv].begin(); it != V[minv].end(); it++) {
      if (E[make_pair(minv, *it)] < INF && d[minv] + E[make_pair(minv, *it)] < d[*it]) {
        d[*it] = d[minv] + E[make_pair(minv, *it)];
        Q.push(make_pair(d[*it], *it));
      }
    }
  }

  REP(i, n) {
    cout << i << " " << d[i] << endl;
  }
  return 0;
}

C++: #include <stdio.h>
#include <cmath>
#include <algorithm>
#include <stack>
#include <queue>
#include <vector>
typedef long long int ll;

#define BIG_NUM 2000000000

using namespace std;

struct Node{

	Node(int arg_to,int arg_cost){
		to = arg_to;
		cost = arg_cost;
	}
	bool operator<(const struct Node &arg) const{
			return cost > arg.cost;
	};

	int to,cost;
};

int main(){

	int N;
	scanf("%d",&N);

	vector<Node> V[N];

	int node,num,to,cost,D[N];;

	for(int loop = 0; loop < N; loop++){
		scanf("%d",&node);
		scanf("%d",&num);
		for(int i = 0; i < num; i++){
			scanf("%d %d",&to,&cost);
			V[node].push_back(Node(to,cost));
		}
		D[loop] = BIG_NUM;
	}

	D[0] = 0;

	priority_queue<Node> Q;

	for(int i = 0; i < V[0].size(); i++){
		D[V[0][i].to] = V[0][i].cost;
		Q.push(Node(V[0][i].to,V[0][i].cost));
	}

	int min_index;

	while(!Q.empty()){
		if(Q.top().cost == D[Q.top().to]){
			min_index = Q.top().to;
			Q.pop();
		}else{
			Q.pop();
			continue;
		}

		for(int k = 0; k < V[min_index].size(); k++){
			if(D[V[min_index][k].to] > D[min_index] + V[min_index][k].cost){
				D[V[min_index][k].to] = D[min_index] + V[min_index][k].cost;
				Q.push(Node(V[min_index][k].to,D[V[min_index][k].to]));
			}
		}
	}

	for(int i = 0; i < N; i++)printf("%d %d\n",i,D[i]);

    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 =10000;
 
struct edge
{
    int to,cost;
    edge(int _to,int _cost){
        to =_to;
        cost =_cost;
    }
};
 
int V;
vector<edge> cost[MAX_N];
int d[MAX_N];
bool visit[MAX_N];
void dijkstra(int s){
    d[s]=0;
    priority_queue<pii, vector<pii> ,greater<pii> > que;
    que.push(mp(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 <cost[v].size();i++){
            edge e =cost[v][i];
            if(d[e.to] >d[v]+e.cost){
                d[e.to] =d[v] +e.cost;
                que.push(mp(d[e.to],e.to));
            }
        }
    }
}
 
int main(){
    cin>>V;
    for(int i =0;i <V;i++){
        d[i]=INF;
        int u,k;
        cin>>u>>k;
        for(int j =0;j <k;j++){
            int to,c;
            cin>>to>>c;
            cost[u].push_back(edge(to,c));
        }
    }
     
    dijkstra(0);
    for(int i =0;i <V;i++){
        cout <<i<<" "<<d[i]<<endl;
    }
    return 0;
}

C++: #include<iostream>
#include<climits>
using namespace std;

typedef struct{
  int A[10010];
  int ans;
}node;
node T[10010];
int Q[10000003];
int head=0;
int tail=1;
int n;

void function(int num){
  while(true){
    if(head==tail)break;
    num=Q[head++];
        if(head==9999999)head=1;
    for(int i=0;i<n;i++){
      if(T[num].A[i]!=-1){
	if(T[i].ans>T[num].ans+T[num].A[i]){
	  T[i].ans=T[num].ans+T[num].A[i];
	  Q[tail++]=i;
	  	  if(tail==9999999)tail=1;
	}
      }
    }
  }
}

int main(){
  int num,son,z,w;
  cin>>n;
  for(int i=0;i<n;i++){
    for(int j=0;j<n;j++){
      T[i].A[j]=-1;
    }
  }


  for(int i=0;i<n;i++){
    cin>>num>>son;
    T[num].ans=INT_MAX;
    for(int j=0;j<son;j++){
      cin>>z>>w;
      T[num].A[z]=w;
      }
  }
  Q[0]=0;
  T[0].ans=0;
  function(0);
 
  for(int i=0;i<n;i++){
      cout<<i<<" "<<T[i].ans<<endl;
  }
  return 0;
}