Go: package main

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

const NIL = -1

type Node struct {
	id     int
	weight int
}

func init() {
	sc.Split(bufio.ScanWords)
}

type NodeHeap []Node

func (h NodeHeap) Len() int           { return len(h) }
func (h NodeHeap) Less(i, j int) bool { return h[i].weight < h[j].weight }
func (h NodeHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *NodeHeap) Push(x interface{}) {
	*h = append(*h, x.(Node))
}

func (h *NodeHeap) Pop() interface{} {
	old := *h
	n := len(old)
	x := old[n-1]
	*h = old[0 : n-1]
	return x
}

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func main() {
	n := scanInt()

	list := make([][]int, n)
	weight := make([]int, n)
	for i := range list {
		list[i] = make([]int, n)
		weight[i] = NIL
		for j := range list[i] {
			list[i][j] = NIL
		}
	}

	for i := 0; i < n; i++ {
		u := scanInt()
		k := scanInt()
		for j := 0; j < k; j++ {
			v := scanInt()
			w := scanInt()
			list[u][v] = w
		}
	}

	start := Node{id: 0, weight: 0}
	h := &NodeHeap{start}
	heap.Init(h)

	for h.Len() > 0 {
		node := heap.Pop(h).(Node)
		if weight[node.id] != NIL {
			continue
		}
		weight[node.id] = node.weight

		for i, w := range list[node.id] {
			if w == NIL {
				continue
			}
			heap.Push(h, Node{id: i, weight: w + node.weight})
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		fmt.Fprint(w, i)
		fmt.Fprint(w, " ")
		fmt.Fprint(w, weight[i])
		fmt.Fprintln(w)
	}
	w.Flush()
}

C++: #include<iostream>
#include<vector>
#include<deque>
#include<queue> 
#include<functional>
#include<climits>

//#define INF 2147483647
#define INF INT_MAX

using namespace std;

int n;
priority_queue<pair<int, int>,  deque<pair<int,int>>, greater<pair<int,int>>> q;
vector<vector<int>> c;
vector<int> d;


int input(){
  cin >> n;
  int u = 0, k = 0, v = 0;
  c.resize(n);
  for( int i = 0; i < n; i++ ){
    cin >> u >> k;
    c[u].resize(n, -1);
    for( int j = 0; j < k; j++ ){
      cin >> v;
      cin >> c[u][v];
    }
  }
  d.resize(n, INF);
  return 0;
}

int checkContinue(){
  for( int i = 0; i < n; i++ ){
    if( d[i] == INF ){ return 1; }
  }
  return 0;
}

int run(){
  q.emplace(pair<int,int>(0,0));
  while( checkContinue() ){
    pair<int, int> p = q.top();
    q.pop();
    if( d[p.second] < p.first ){ continue; }
    d[p.second] = p.first;
    for( int i = 0; i < n; i++ ){
      if( c[p.second][i] < 0 ){ continue; }
      q.push(pair<int,int>(p.first+c[p.second][i], i));
      // cout << p.first+c[p.second][i] << "," << i << endl;
    }
  }
  for( int i = 0; i < n; i++ ){
    cout << i << " " << d[i] << endl;
  }
  return 0;
}

int main(){
  input();
  run();
  return 0;
}

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

using namespace std;
using ll = long long int;
#define rep(i,n) for(int i = 0; i < n; i++)
#define FOR(i, a, b)  for(int i = (a); i < (b) ; i++)

#define pb push_back
#define SORT(v,n) sort(v, v+n)
#define ALL(x) (x).begin(),(x).end()
#define debug(x) cerr << #x << ": " << x << '\n'
#define elif else if
#define itn ll
#define int ll
const int INF = 100100100;
const int MOD = (int)1e9 + 7;
const double EPS = 1e-9;
///                →,↑,←,↓,↗,↖,↙,↘
int dx[8] = { 1, 0, -1, 0, 1, -1, -1, 1 };
int dy[8] = { 0, 1, 0, -1, 1, 1, -1, -1 };

typedef vector<vector<int>> vvi;
typedef vector<vector<vector<int>>> vvvi;

static const int MAX = 100;
static const int White = 0;
static const int Gray = 1;
static const int Black = 2;


int n, M[MAX][MAX];
int d[MAX], p[MAX],color[MAX];

void dijkstra() {
	rep(i, n) {
		color[i] = White;
		d[i] = INF;
		p[i] = -1;
	}
	d[0] = 0;
	while (true) {
		int u, mincost = INF;
		rep(i, n) {
			if (color[i] != Black and d[i] < mincost) {
				u = i;
				mincost = d[i];
			}
		}
		if (mincost == INF) break;
		color[u]  = Black;
		int v;
		rep(v, n) {
			if (color[v] != Black and M[u][v] != INF) {
				if (d[u] + M[u][v] < d[v]) {
					d[v] = d[u] + M[u][v];
					p[v] = u;
					color[v] = Gray;
				}
			}
		}
	}
	rep(i, n) {
		cout << i << ' ' << d[i] << '\n';
	}
}

signed main() {
	ios::sync_with_stdio(false);
	int i, j, k;
	cin >> n;
	rep(i, n) {
		rep(j, n) {
			M[i][j] = INF;
		}
	}
	rep(i, n) {
		int u, k;
		cin >> u >> k;
		rep(j, k) {
			int c,v;
			cin >> v >> c;
			M[u][v] = c;
		}
	}
	dijkstra();
	return 0;
}

C++: #include<stdio.h>

#define N 103
#define INF 10000000
#define NIL -1
#define BLACK 1

int G[N][N];

int d[N],pi[N],color[N];
int ci[N];
int v[N];

int num;

void initialize(int);
void dij(int);

int main(){
  int i,j;
  int k,u;
  int start=0;

  scanf("%d",&num);

  for(i=0;i<num;i++){
    for(j=0;j<num;j++){
      G[i][j] = NIL;
    }
  }
  

  for(i=0;i<num;i++){
    scanf("%d%d",&u,&k);
      for(j=0;j<k;j++){
	scanf("%d%d",&v[j],&ci[j]);
	G[u][v[j]] = ci[j]; 
      }
  }

  dij(start);

  /*for(i=0;i<num;i++){
    for(j=0;j<num;j++){
      printf("%d ",G[i][j]);
    }
    printf("\n");
  }
  */

  for(i=0;i<num;i++){
    printf("%d %d\n",i,d[i]);
  }
  
  return 0;

}

void initialize(int s){
  int v;
  for(v=0;v<num;v++){
    d[v] = INF;
    pi[v] = NIL;
  }

  d[s] = 0;
}

void dij(int s){
  int mincost;
  int i,v,u;
  
  initialize(s);

  while(1){
    
    mincost = INF;

    for(i=0;i<num;i++){
      
      if(color[i] != BLACK && d[i] < mincost){
	mincost = d[i];
	u = i;

      }
    }

    //printf("u=%d\n", u);
    if(mincost == INF) break;

    color[u] = BLACK;
    
    for(v=0;v<num;v++){
      
      if(G[u][v] == -1) continue;
      if(color[v] != BLACK && d[u] + G[u][v] < d[v]){
	pi[v]= u;
	d[v] = d[u] + G[u][v];
      }
    }
  }
}