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<cstdio>
#include<string>
#include<algorithm>
#include<cstring>
#include<vector>
#include<queue>
using namespace std;
#define INT(x) int x; scanf("%d",&x)
#define INPUT(x) scanf("%d",&x)
#define REP1(x,n) for(int x = 0; x < n; x++)
#define REP2(x,s,e) for(int x = s; x <= e; x++)
#define BR printf("\n")
#define INF 2000000000

class edge{
public:
    int toid;
    int norm;
    int dist;
    edge(int toid,int norm,int dist){
        this -> toid = toid;
        this -> norm = norm;
        this -> dist = dist;
    }
    bool operator < (const edge &E) const {
        return dist < E.dist;
    }
    bool operator > (const edge &E) const {
        return dist > E.dist;
    }
};

vector<edge> V[10000];
int d[10000];
int count_P = 0;
priority_queue<edge,vector<edge>,greater<edge> > PQ;

void Dijksra(int i,int dist,int n){
    PQ.pop();
    d[i] = dist;
    count_P++;
    if(count_P == n) return;
    
    REP1(k,V[i].size()){
        if (d[V[i][k].toid] == INF && V[i][k].dist > dist + V[i][k].norm){
            V[i][k].dist = dist + V[i][k].norm;
            PQ.push(V[i][k]);
        }
    }
    
    while (d[PQ.top().toid] != INF) PQ.pop();
    if (!PQ.empty()) Dijksra(PQ.top().toid,PQ.top().dist,n);
}

int main(){
    INT(N);
    REP1(i,N) d[i] = INF;
    REP1(i,N){
        int from,n;
        scanf("%d %d",&from,&n);
        REP1(j,n){
            int toid,norm;
            scanf("%d %d",&toid,&norm);
            edge E = edge(toid,norm,INF);
            V[i].push_back(E);
        }
    }
    
    PQ.push(edge(0,0,0));
    Dijksra(PQ.top().toid,0,N);
    
    REP1(i,N){
        printf("%d %d\n",i,d[i]);
    }
    
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
static const int INF   = (1 << 21);
static const int WHITE = 0;
static const int GRAY  = 1;
static const int BLACK = 2;
static const int NIL   = -1;
static const int MAX   = 10000;

int n;
vector<vector<pair<int, int>>> M(MAX);

void dijstra(int s) {
  vector<int> color(n, WHITE);
  vector<int> d(n, INF);
  d[s] = 0;
  priority_queue<pair<int, int>> pq;
  pq.push(make_pair(0, 0));

  while (!pq.empty()) {
    pair<int, int> tmp = pq.top();
    pq.pop();

    int u    = tmp.second;
    color[u] = BLACK;
    if (d[u] < tmp.first * (-1)) continue;

    int size = M[u].size();
    for (int i = 0; i < size; i++) {
      int v = M[u][i].second;
      if (color[v] == BLACK) continue;

      if (d[u] + M[u][i].first < d[v]) {
        d[v]     = d[u] + M[u][i].first;
        color[v] = GRAY;
        pq.push(make_pair(d[v] * (-1), v));
      }
    }
  }
  int res = 0;
  for (int i = 0; i < n; i++) {
    cout << i << " " << d[i] << endl;
  }
}

int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    int id, k;
    cin >> id >> k;
    for (int j = 0; j < k * 2; j += 2) {
      pair<int, int> p;
      cin >> p.second >> p.first;
      M[id].push_back(p);
    }
  }
  dijstra(0);
}

C++: #include <functional>
#include <queue>
#include <stdio.h>
#include <utility>
#include <vector>

static const int MAX = 10000;
static const int INFINITY = 1 << 20;
static const int WHITE = 0;
static const int GRAY  = 1;
static const int BLACK = 2;

static int n;
static std::vector<std::pair<int, int> > adj[MAX];

void dijkstra()
{
    std::priority_queue<std::pair<int, int>, std::vector<std::pair<int, int>>, std::greater<std::pair<int, int>> > PQ;
    int color[MAX];
    int d[MAX];

    for (int i = 0; i < n; i++) {
        d[i] = INFINITY;
        color[i] = WHITE;
    }

    d[0] = 0;
    PQ.push(std::make_pair(0, 0));
    color[0] = GRAY;

    while (!PQ.empty()) {
        std::pair<int, int> f = PQ.top();
        PQ.pop();
        int u = f.second;
        color[u] = BLACK;
    
        if (d[u] < f.first)
            continue;

        for (int i = 0; i < adj[u].size(); i++) {
            int v = adj[u][i].first;
            if (color[v] == BLACK)
                continue;
            if (d[v] > d[u] + adj[u][i].second) {
                d[v] = d[u] + adj[u][i].second;
                PQ.push(std::make_pair(d[v], v));
                color[v] = GRAY;
            }
        }
    }

    for (int i = 0; i < n; i++) {
        printf("%d %d\n", i, (d[i] == INFINITY) ? -1 : d[i]);
    }
}

int main()
{
    scanf("%d", &n);
    
    for (int i = 0; i < n; i++) {
        int u, k;
        scanf("%d %d", &u, &k);
        for (int j = 0; j < k; j++) {
            int v, c;
            scanf("%d %d", &v, &c);
            adj[u].push_back(std::make_pair(v, c));
        }
    }
    
    dijkstra();
    return 0;
}

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

using namespace std;
using graph = vector<vector<int>>;


struct edge {
    int src;
    int dst;
    int weight;

    edge(int src, int dst, int w) : src(src), dst(dst), weight(w) {}
};

bool operator < (const edge &a, const edge &b) {
  return a.weight > b.weight;
}


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

    graph G(n, vector<int>(n, -1));
    for (int i = 0; i < n; ++i) {
        int u, k;
        cin >> u >> k;

        for (int j = 0; j < k; ++j) {
            int v, c;
            cin >> v >> c;
            G[u][v] = c;
        }
    }

    // Dijkstra's algorithm (with pritority queue)
    vector<int> d(n, -1);
    vector<bool> visited(n, false);
    priority_queue<edge> Q;

    Q.push(edge(-1, 0, 0));
    while (!Q.empty()) {
        auto e = Q.top(); Q.pop();
        if (visited[e.dst])
            continue;
        d[e.dst] = e.weight;
        visited[e.dst] = true;

        int i = e.dst;
        int minw = numeric_limits<int>::max();
        for (int j = 0; j < n; ++j) {
            if (visited[j] || G[i][j] < 0)
                continue;
            int w = G[i][j] + d[i];
            Q.push(edge(i, j, w));
        }
    }

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

    return 0;
}