Go: package main

import (
	"bufio"
	"container/heap"
	"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
const INF = 1 << 60

type Edge struct {
	to, cost int
}

type Node struct {
	id, cost int
}

type PQ []Node

func (pq PQ) Len() int           { return len(pq) }
func (pq PQ) Less(i, j int) bool { return pq[i].cost < pq[j].cost }
func (pq PQ) Swap(i, j int)      { pq[i], pq[j] = pq[j], pq[i] }

func (pq *PQ) Push(x interface{}) {
	*pq = append(*pq, x.(Node))
}

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

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	E := make([][]Edge, N)
	for i := 0; i < N; i++ {
		id, k := sc.nextInt(), sc.nextInt()
		E[id] = make([]Edge, k)
		for j := 0; j < k; j++ {
			to, cost := sc.nextInt(), sc.nextInt()
			E[id][j] = Edge{to, cost}
		}
	}

	d := make([]int, N)
	for i := 0; i < N; i++ {
		d[i] = INF
	}
	done := make([]bool, N)
	pq := &PQ{}
	heap.Init(pq)
	d[0] = 0
	heap.Push(pq, Node{0, 0})
	for pq.Len() > 0 {
		cur := heap.Pop(pq).(Node).id
		if done[cur] {
			continue
		}
		done[cur] = true
		for i := 0; i < len(E[cur]); i++ {
			to, cost := E[cur][i].to, E[cur][i].cost+d[cur]
			if !done[to] && cost < d[to] {
				d[to] = cost
				heap.Push(pq, Node{to, cost})
			}
		}
	}

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

C++: #include <bits/stdc++.h>
#define FOR(i, a, b) for (int i = (a), i##_max = (b); i < i##_max; ++i)
#define RFOR(i, a, b) for (int i = (b)-1, i##_min = (a); i >= i##_min; --i)
#define REP(i, n) for (int i = 0, i##_len = (n); i < i##_len; ++i)
#define RREP(i, n) for (int i = (n)-1; i >= 0; --i)
#define ALL(obj) (obj).begin(), (obj).end()

using namespace std;
using vi = vector<int>;
using vd = vector<double>;
using pi = pair<int, int>;
using i64 = int64_t;

constexpr int INF = 1 << 30;
constexpr int MOD = 1000000007;

template <typename T>
void print(vector<T> &v) {
  REP(i, v.size()) {
    if (i) cout << " ";
    cout << v[i];
  }
  cout << endl;
}

void dijkstra(vector<vector<pi>> &adj) {
  auto n = adj.size();
  priority_queue<pi> PQ;
  vi d(n, INF);
  vector<bool> visited(n, false);
  d[0] = 0;
  PQ.push(make_pair(0, 0));
  while (!PQ.empty()) {
    auto f = PQ.top();
    PQ.pop();
    auto u = f.second;
    visited[u] = true;
    if (d[u] < -f.first) continue;
    REP(i, adj[u].size()) {
      auto v = adj[u][i].first;
      auto new_cost = d[u] + adj[u][i].second;
      if (!visited[v] && new_cost < d[v]) {
        d[v] = new_cost;
        PQ.push(make_pair(-d[v], v));
      }
    }
  }
  REP(i, n) cout << i << " " << (d[i] == INF ? -1 : d[i]) << endl;
}

int main() {
  int n;
  cin >> n;
  vector<vector<pi>> adj(n);
  int k, c, u, v;
  REP(i, n) {
    cin >> u >> k;
    REP(j, k) {
      cin >> v >> c;
      adj[u].push_back(make_pair(v, c));
    }
  }
  dijkstra(adj);
}

C++: #include <iostream>
#include <algorithm>
#include <vector>
#include <deque>
#include <queue>
#include <list>
#include <stack>
#include <string>
#include <tuple>
#include <functional>
#include <numeric>
#include <cmath>
#include <iomanip>
#include <map>
#include <random>
#include <cstdlib>
#define INT_MAX 2147483647
#define INT_MIN -2147483646
#define Loop(i, n) for(int i = 0; i < (int)n; i++)
#define Loop1(i, n) for(int i = 1; i <= (int)n; i++)
#define Loopr(i, n) for(int i = (int)n - 1; i >= 0; i--)
#define Loopr1(i, n) for(int i = (int)n; i >= 1; i--)
using namespace std;
typedef long long int ll;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;

static const int N = 105;

struct vertex {
	int id;
	int p;
	int d;
	bool operator<(const vertex & another) const {
		return (d != another.d ? d>another.d : id>another.id);
	}
};

struct edge {
	int end;
	int w;
};

int main() {
	int n;
	cin >> n;
	vector<vector<edge>> E(N);
	Loop(i, n) {
		int u, k;
		cin >> u >> k;
		Loop(i, k) {
			int v, c;
			cin >> v >> c;
			E[u].push_back({ v,c });
		}
	}
	//
	priority_queue<vertex> pq;
	vi color(N, 0), dist(N, 0);
	pq.push({ 0,-1,0 });
	while (pq.size() > 0) {
		vertex v = pq.top();
		pq.pop();
		if (color[v.id] == 1) continue;
		dist[v.id] = v.d;
		color[v.id] = 1;
		Loop(j, E[v.id].size()) {
			pq.push({ E[v.id][j].end, v.id, dist[v.id] + E[v.id][j].w });
		}
	}
	Loop(i, n) {
		cout << i << " " << dist[i] << endl;
	}
	return 0;
}

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 rep(x,n) for(int x = 0; x < n; x++)
#define _br printf("\n")
#define INF 2000000000

vector<pair<int,int> > PathList[10000];
int d[10000];
bool complete[10000];

void dijkstra(int n,vector<pair<int,int> > PathList[]){
    priority_queue<pair<int,int> > PQ;
    
    rep(i,n){
        d[i] = INF;
        complete[i] = false;
    }
    d[0] = 0;
    PQ.push(make_pair(-d[0],0));
    int count = 0;
    
    while (count != n) {
        //select
        int mindi;
        while (1) {
            if (!complete[PQ.top().second]) {
                mindi = PQ.top().second;
                PQ.pop();
                break;
            }
            PQ.pop();
        }
        
        complete[mindi] = true;
        count++;
        
        //update
        rep(i,PathList[mindi].size()){
            if (PathList[mindi][i].second + d[mindi] < d[PathList[mindi][i].first]) {
                d[PathList[mindi][i].first] = PathList[mindi][i].second + d[mindi];
                PQ.push(make_pair(-(PathList[mindi][i].second + d[mindi]),PathList[mindi][i].first));
            }
        }
    }
}


int main(){
    int(n);
    rep(i,n){
        int(k);int(num);
        rep(j,num){
            int(s);int(t);
            PathList[i].push_back(make_pair(s,t));
        }
    }
    
    dijkstra(n,PathList);
    
    rep(i,n){
        printf("%d %d\n",i,d[i]);
    }
    
    return 0;
}