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<cstdio>
#include<algorithm>
#define Lens 101
#define Inf 1<<22

using namespace std;
int N;
int w[Lens][Lens],p[Lens],d[Lens];
char c[Lens];

void dijkstra()
{
	d[0] = 0;
	while (true)
	{
		int u = -1;
		int minv = Inf;
		for (int i = 0; i < N; i++)
		{
			if (c[i] == 'w'&&minv > d[i])
			{
				minv = d[i];
				u = i;
			}
		}
		if (u == -1) break;
		c[u] = 'b';
		for (int v = 0; v < N; v++)
		{
			if (c[v] == 'w'&&w[u][v] != Inf)
				d[v] = min(d[v], w[u][v]+d[u]);
		}
	}
}

int main()
{
	cin >> N;
	for (int i = 0; i < N; i++)
	{
		c[i] = 'w';
		d[i] = Inf;
		p[i] = -1;
		int u,n;
		cin >> u >> n;
		for (int j = 0; j < n; j++)
		{
			int v, tw;
			cin >> v >> tw;
			w[u][v] = tw;
		}
	}
	for(int i=0;i<N;i++)
		for (int j = 0; j < N; j++)
		{
			if (w[i][j] == 0)
				w[i][j] = Inf;
		}
	dijkstra();
	for (int i = 0; i < N; i++)
		cout << i <<' '<< d[i] << endl;
	return 0;
}

C++: //
//  ALDS_12_B.cpp
//  
//
//  Created by 杵鞭俊 on 2018/07/24.
//

#include <iostream>
using namespace std;
static const int MAX=100;
static const int INFTY=(1<<21);
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;

int n ,M[MAX][MAX];

void dijkstra(){
    int minv;
    int d[MAX],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(minv>d[i]&&color[i]!=BLACK){
                u=i;
                minv=d[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]) <<endl;
    }
}

int main(){
    cin >> n;
    for (int i=0; i<n; i++) {
        for (int j=0; j<n; j++) {
            M[i][j]=INFTY;
        }
    }
    int k,c,u,v;
    for (int i=0; i<n; i++) {
        cin >> u >> k;
        for (int j=0; j<k; j++) {
            cin >> v >> c;
            M[u][v]=c;
        }
    }
    
    dijkstra();
    return 0;
}

C++: #define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <stdio.h>
#include <cstring>
#define maxn 101
#define INF 0x3f3f3f3f
using namespace std;

int m[maxn][maxn] = {}, d[maxn] = {}, color[maxn] = {};
int n;

void Dijkstra()
{
	for (int i = 1; i < n; i++)
		d[i] = INF;
	d[0] = 0;
	while (true)
	{
		int mincost = INF,u;
		for(int i=0;i<n;i++)
			if (d[i] < mincost&&color[i]==0)
			{
				mincost = d[i];
				u = i;
			}
		if (mincost == INF)break;
		color[u] = 1;
		for (int i = 0; i < n; i++)
			if (color[i] == 0 && m[u][i] != -1)
				if (d[i] > d[u] + m[u][i])
					d[i] = d[u] + m[u][i];
	}
}
int main()
{
	scanf("%d", &n);
	memset(m, -1, sizeof(m));
	for (int i = 0; i < n; i++)
	{
		int u, k;
		scanf("%d %d", &u, &k);
		for (int i = 0; i < k;i++)
		{
			int v, c;
			scanf("%d%d", &v, &c);
			m[u][v] = c;
		}
	}
	Dijkstra();
	for (int i = 0; i < n; i++)
	{
		printf("%d %d\n", i, d[i]);
	}
	return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;

const int INF = 1 << 30;

struct edge {
	int cost; //重み(距離)
	int to; //行先の頂点
};

void dijkstra(const int n, const vector<vector<edge>> &G, const int stpoint) {

	//優先キューは最短距離と頂点番号のペア、 距離を降順に並べる
	priority_queue<pair<int, int>,vector<pair<int,int>>,greater<pair<int,int>>> pq;

	vector<bool> seen(n,false); //訪問完了でtrue
	vector<int> cost(n,INF); //頂点nまでの距離

	cost[stpoint] = 0;
	pq.push(make_pair(0, 0));

	while (pq.empty() == false) {

		//ターゲット頂点設定（すでに決定したものの中のどれか）
		pair<int, int> target = pq.top();
		int tnum = target.second; //ターゲット頂点番号
		pq.pop();
		
		seen[tnum] = true;

		if (cost[tnum] < target.first) { continue; } //これの意味が分からない保留

		for (unsigned int j = 0; j < G[tnum].size(); j++) { //ターゲットから繋がる先を全部探す

			int v = G[tnum][j].to; //繋がる先の頂点をvにする

			if (seen[v] == true) { continue; } //もう見たとこ（仲間に入ってる）ならスキップ

			if (cost[v] > cost[tnum] + G[tnum][j].cost) {
				cost[v] = cost[tnum] + G[tnum][j].cost;
				pq.push(make_pair(cost[v], v));
			}
		}
	}

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

}

int main() {

	int n;
	cin >> n;

	int stpoint = 0; //この問題では0起点

	vector<vector<edge>> G(n);

	int in1, in2, in3, in4;
	for (int i = 0; i < n; i++) {
		cin >> in1 >> in2;
		for (int j = 0; j < in2; j++) {
			cin >> in3 >> in4;
			G[in1].push_back({ in4, in3 });
		}
	}

	dijkstra(n,G,stpoint);

	return 0;
}