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 <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>

#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define repi(i,a,b) for(int i = (a); i < (b); i++)

using namespace std;

typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;

const int INF=1<<29;
const double EPS=1e-9;

const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};
const int MAX_N =10000;

struct edge
{
	int to,cost;
	edge(int _to,int _cost){
		to =_to;
		cost =_cost;
	}
};

int V;
vector<edge> cost[MAX_N];
int d[MAX_N];
bool visit[MAX_N];
void dijkstra(int s){
	d[s]=0;
	priority_queue<pii, vector<pii> ,greater<pii> > que;
	que.push(mp(0,s));
	while(!que.empty()){
		pii p =que.top();
		que.pop();
		int v =p.second;
		if(d[v] < p.first)continue;
		for(int i =0;i <cost[v].size();i++){
			edge e =cost[v][i];
			if(d[e.to] >d[v]+e.cost){
				d[e.to] =d[v] +e.cost;
				que.push(mp(d[e.to],e.to));
			}
		}
	}
}

int main(){
	cin>>V;
	for(int i =0;i <V;i++){
		d[i]=INF;
		int u,k;
		cin>>u>>k;
		for(int j =0;j <k;j++){
			int to,c;
			cin>>to>>c;
			cost[u].push_back(edge(to,c));
		}
	}
	
	dijkstra(0);
	for(int i =0;i <V;i++){
		cout <<i<<" "<<d[i]<<endl;
	}
	return 0;
}

C++: // 単一始点最短経路 ( ダイクストラ法 : 優先度付きキュー )
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<stack>
#include<algorithm>
#include<iostream>
#include<cmath>
#include<vector>

#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;

// 重み付き有向グラフの隣接リスト表現
// first : 頂点No. second : 入力される辺の重み
vector< pair<int, int> > adj[MAX];

int Dijkstra()
{
    int u;
    int d[MAX], p[MAX], color[MAX];

    // 優先度付きキュー : first : 最短距離 second : 頂点No.
    priority_queue< pair<int, int> > PQ;

    for(int i = 0; i < n; i++)
    {
        d[i] = INFTY;
        p[i] = -1;
        color[i] = WHITE;
    }

    // 初期値の設定
    d[0] = 0;
    PQ.push( make_pair(0, 0) );
    color[0] = GRAY;

    while( !PQ.empty() )
    {
        pair<int, int> f = PQ.top();
        PQ.pop();

        // 次に移動するべき頂点
        u = f.second;;
        // 訪問完了
        color[u] = BLACK;

        // 最小値を取り出し, それが最短で無ければ無視
        if( d[u] < f.first * (-1) )
        {
            continue;
        }

        for(int j = 0; j < adj[u].size(); j++)
        {
            // 隣接リストから要素を取得する
            int v = adj[u][j].first;

            if( color[v] != BLACK )
            {
                // u → v の経路の中で, vのコストが最小のものが見つかれば更新する
                if( d[v] > d[u] + adj[u][j].second )
                {
                    // コストの記録
                    d[v] = d[u] + adj[u][j].second;
                    // 頂点 v の親を記録する
                    p[v] = u;
                    // 訪問状態の記録
                    color[v] = GRAY;

                    // キューに要素を入れる
                    // priority_queue はデフォルトで大きい値を優先するため, -1を掛ける
                    PQ.push( make_pair( d[v] * (-1), v ) );
                }
            }
        }
    }

    // 結果の表示
    for(int i = 0; i < n; i++)
    {
        cout << i << " " << ( d[i] == INFTY ? -1 : d[i] ) << endl;
    }

    return 0;
}

int main(void)
{

    int k, c, u, v;

    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<bits/stdc++.h>
#define REP(i,n) for(int i=0;i<(int)(n);i++)
using namespace std;

struct edge { int from, to, cost; };
const int MAX_V=100;
const int INF=1e9;

vector<edge> es;
int d[MAX_V];
int n;

void shortest_path(int s){
  REP(i, n) d[i] = INF;
  d[s] = 0;
  while(true){
    bool update = false;
    for(edge e : es){
      if(d[e.from] != INF && d[e.to] > d[e.from] + e.cost){
	d[e.to] = d[e.from] + e.cost;
	update = true;
      }
    }
    if(!update) break;
  }
}

int main(){
  cin>>n;
  REP(i,n){
    int u, k; cin>>u>>k;
    REP(j,k){
      edge e;
      e.from = u;
      cin>>e.to>>e.cost;
      es.push_back(e);
    }
  }
  shortest_path(0);
  REP(i,n){
    cout<<i<<" "<<d[i]<<endl;
  }
}