Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
type Node struct {
	cost int
	done bool
}

type Edge struct {
	to, cost int
}

const INF = 1 << 60

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	nodes := make([]Node, N)
	for i := 0; i < N; i++ {
		nodes[i].cost = INF
	}
	E := make([][]Edge, N)
	for i := 0; i < N; i++ {
		id, k := sc.nextInt(), sc.nextInt()
		for j := 0; j < k; j++ {
			to, cost := sc.nextInt(), sc.nextInt()
			E[id] = append(E[id], Edge{to, cost})
		}
	}
	nodes[0].cost = 0
	for {
		cur := 0
		minCost := INF
		for i := 0; i < N; i++ {
			n := nodes[i]
			if !n.done && n.cost < minCost {
				cur = i
				minCost = n.cost
			}
		}
		if minCost == INF {
			break
		}
		nodes[cur].done = true
		for i := 0; i < len(E[cur]); i++ {
			to, cost := E[cur][i].to, E[cur][i].cost+nodes[cur].cost
			if !nodes[to].done && cost < nodes[to].cost {
				nodes[to].cost = cost
			}
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i, nodes[i].cost)
	}
	wtr.Flush()
}

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 color[MAX];
	int d[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 (unsigned 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, 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;
			adj[u].push_back(make_pair(v, c));
		}
	}

	dijkstra();

	return 0;
}

C++: #include <iostream>
 using namespace std;
 static const int WHITE = 0;
 static const int GRAY = 1;
 static const int BLACK =2;
 static const int MAX = 100;
 static const int INFTY = (1<<21);
 
 int n,M[MAX][MAX];
 
 void dijks(){
 	int minv;
 	int d[MAX],p[MAX];
 	int color[MAX];
 	for(int i=0;i<n;i++){
 		d[i] = INFTY;
 		color[i] = WHITE;
 	}
 	
 	d[0] = 0;
 	color[0] = GRAY;
 	while(1){
 		minv = INFTY;
 		int u=-1;
 		for(int i=0;i<n;i++){
 			if(color[i]!=BLACK&&d[i]<INFTY){
 				minv = d[i];
 				u=i;
 			}
 		}
 		
 		if(u==-1) break;
 		
 		color[u] = BLACK;
 		
 		for(int v=0;v<n;v++){
 			if(color[v]!=BLACK&&M[u][v]<INFTY){
 				if(d[v]>d[u]+M[u][v]){
 					d[v] = d[u]+M[u][v];
 					color[v] = GRAY;
 				}
 			}
 		}
 	}
 	
 	for(int i=0;i<n;i++){
 		cout<<i<<" "<<(d[i]==INFTY?-1:d[i]);
 	}
 }
 
 int main(){
 	cin>>n;
 	
 	for(int i=0;i<n;i++){
 		for(int j=0;j<n;j++){
 			M[i][j] = INFTY;
 		}
 	}
 	
 	int k,u,c,v;
 	for(int i=0;i<n;i++){
 		cin>>u>>k;
 		for(int j=0;j<k;j++){
 			cin>>c>>v;
 			M[u][c] = v;
 		}
 	}
 	dijks();
 	return 0;
 }

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

struct Edge {int to, cost;};

typedef vector<Edge> Edges;
typedef vector<Edges> Graph;

int mind(vector<int> &a,vector<int> &b){
	int n=a.size();
	int min=INT_MAX;
	int ind=0;
	for (int i=0;i<n;i++){
		if((min>a[i])&&(b[i]==0)){
			min=a[i];
			ind=i;
		}
	}
	if(min==INT_MAX){
		return -1;
	}else{
		return ind;
	}
}

int min(vector<int> &a){
	int n=a.size();
	int min=a[0];
	int ind=0;
	for (int i=0;i<n;i++){
		if(min>a[i]){
			min=a[i];
			ind=i;
		}
	}
	return min;
}

void dijkstra(Graph &G,vector<int> &d,int n,int s){
	fill(d.begin(),d.end(),INT_MAX);
	vector<int> c(n,0);
	int t;
	
	d[s]=0;
	
	while((t=mind(d,c))!=-1){
		c[t]=1;
		for(int i=0;i<G[t].size();i++){
			Edge e=G[t][i];
			if(d[e.to] > d[t]+e.cost){
				d[e.to] = d[t]+e.cost;
			}
		}
	}
}

int main(){
	int n,i,j,k;
	vector<int> d(n);
	Edge e;
	
	cin >> n;
	
	Graph G(n);
	
	for (i=0;i<n;i++){
		cin >> k >> k;
		for (j=0;j<k;j++){
			cin >> e.to >> e.cost;
			G[i].push_back(e);
		}
	}
	
	dijkstra(G,d,n,0);
	
	for (i=0;i<n;i++){
		cout << i << " " << d[i] << endl;
	}
	
	return 0;
}