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 <bits/stdc++.h>
using namespace std;
#define REP(i,a) for(int i = 0; i < (a); i++)
#define ALL(a) (a).begin(),(a).end()
typedef long long ll;
typedef pair<int, int> P;
const int INF = 1e9;
const int MOD = 1e9 + 7;
#define MAX_V 10000

struct edge { int to, cost; };

int V;
vector<edge> G[MAX_V];
int d[MAX_V];//頂点sからの最短距離

//始点sから各頂点への最短距離を求める
void dijkstra(int s){
	priority_queue<P, vector<P>, greater<P> > que;
	fill(d, d + V, INF);
	d[s] = 0;
	que.push(P(0, s));
    
	while(!que.empty()){
		P p = que.top();
		que.pop();
		int v = p.second;
		if(d[v] < p.first) continue;
		for(int i = 0; i < G[v].size(); i++){
			edge e = G[v][i];
			if(d[e.to] > d[v] + e.cost){
				d[e.to] = d[v] + e.cost;
				que.push(P(d[e.to], e.to));
			}
		}
	}
}


signed main(){
    cin >> V;
    REP(i,V){
        int u,k;
        cin >> u >> k;
        int v,c;
        REP(i,k){
            cin >> v >> c;
            G[u].push_back((edge){v, c});
        }
    }
    dijkstra(0);
    REP(i,V){
        cout << i << " " << d[i] << endl;
    }
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <climits>
#include <string>
#include <vector>
#include <utility>
#include <functional>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <cassert>

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

const ll MOD = ll(1e9) + 7;
const ll INF = LLONG_MAX;
const ll MAX_N = ll(1e5) + 5;
const double EPS = 10e-8;
const double PI = 3.14159265359;

#define REP(i, n) for (ll i = 0; i < n; i++)
#define REPR(i, n) for (ll i = n; i >= 0; i--)
#define FOR(i, m, n) for (ll i = m; i < n; i++)

int dx[] = {1, 0, -1, 0}, dy[] = {0, 1, 0, -1};

struct UF {
    static const int MAX_N = 100000;
    int p[MAX_N];
    int r[MAX_N];

    void init(int n) {
        REP(i, n) {
            p[i] = i;
            r[i] = 0;
        }
    }
    int find(int x) {
        if (p[x] == x) return x;
        return p[x] = find(p[x]);
    }
    void unite(int x, int y) {
        x = find(x);
        y = find(y);
        if (x == y) return;
        if (r[x] < r[y]) swap(x, y);
        if (r[x] == r[y]) r[x]++;
        p[y] = x;
    }
    bool same(int x, int y) { return find(x) == find(y); }
};

int n, d[100];
vector<P> g[100];

void dijkstra(int s) {
    fill(d, d + n, 99999999);
    d[s] = 0;
    priority_queue<P> que;
    que.push({0, s});
    while (!que.empty()) {
        P p = que.top();
        que.pop();
        int u = p.second;
        if (p.first > d[u]) continue;
        REP(i, g[u].size()) {
            int v = g[u][i].first, cost = g[u][i].second;
            if (d[v] > d[u] + cost) {
                d[v] = d[u] + cost;
                que.push({d[v], v});
            }
        }
    }
}

int main() {
    cin >> n;
    REP(i, n) {
        int from, k;
        cin >> from >> k;
        REP(j, k) {
            int to, c;
            cin >> to >> c;
            g[from].push_back({to, c});
        }
    }
    dijkstra(0);
    REP(i, n) { cout << i << " " << d[i] << endl; }
    return 0;
}

C++: #include <stdio.h>
#include <iostream>
#include <vector>
using namespace std;

#define NUM 100
#define NIL -1
#define INF 1000000000
#define WHITE 0
#define BLACK 1
int node_num;
vector<tuple<int, int>> G[NUM];
int V[NUM];
int color[NUM];

void init(void){
    scanf("%d", &node_num);

    for(int i = 0; i < node_num; i++){
        int u, k;
        scanf("%d", &u);
        scanf("%d", &k);

        for(int j = 0; j < k; j++){
            int v_, c;
            scanf("%d", &v_);
            scanf("%d", &c);
            G[u].push_back(make_tuple(v_, c));
        }
    }

    for(int i = 0; i < node_num; i++){
        color[i] = WHITE;
        V[i] = INF;
    }
}

void updateAround(int n){
    color[n] = BLACK;
    for(int i = 0; i < G[n].size(); i++){
        V[get<0>(G[n][i])] = min(V[get<0>(G[n][i])], V[n] + get<1>(G[n][i]));
    }

    int min_index = NIL;
    int min_value = INF;
    for(int i = 0; i < node_num; i++){
        if(color[i] == BLACK){
            continue;
        }
        if(V[i] < min_value){
            min_value = V[i];
            min_index = i;
        }
    }
    if(min_index != NIL){
        updateAround(min_index);
    }
}

int main(void){
    init();

    V[0] = 0;
    updateAround(0);

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

C++: #include <iostream>
#include <vector>
#include <stack>
#include <queue>
#include <cmath>
#include <algorithm>
using namespace std;

void solve(){
  int n; cin >> n;
  vector<vector<int> > v(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 a, b; cin >> a >> b;
      v[u][a] = b;
    }
  }
  vector<int> t, c(n), d(n, 10000000);
  d[0] = 0;
  while(t.size() != n){
    int mini, mind = 10000000;
    for(int i = 0; i < n; i++){
      if(c[i] == 0){
        if(d[i] < mind){
          mini = i;
          mind = d[i];
        }
      }
    }
    t.push_back(mini);
    c[mini] = 1;
    for(int i = 0; i < n; i++){
      if(v[mini][i] >= 0 && c[i] == 0) d[i] = min(v[mini][i] + d[mini], d[i]);
    }
  }
  for(int i = 0; i < n; i++){
    cout << i << " " << d[i] << endl;
  }
  return;
}

int main(){
  solve();
  return 0;
}