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 <cstdio>
#include <cstring>
#include <climits>
#include <vector>
#include <map>
using namespace std;

typedef vector<int>::iterator vitr;
typedef map<int, int>::iterator mitr;

map<int, int> w[100];
int d[100];

vector<int> others;

void findPath(){
    int candiW = INT_MAX;
    vitr candiI;
    for(vitr i=others.begin();i!=others.end();i++){
        if(d[*i] < candiW){
            candiI = i;
            candiW = *i;
        }
    }

    for(mitr i=w[*candiI].begin();i!=w[*candiI].end();i++){
        if(i->second + d[*candiI] < d[i->first]){
            d[i->first] = i->second + d[*candiI];
        }
    }

    others.erase(candiI);
}

int main(){
    int i,j,u,k,n,v,c;


    scanf("%d",&n);
    for(i=0;i<n;i++){
        scanf("%d %d",&u,&k);
        for(j=0;j<k;j++){
            scanf("%d %d",&v,&c);
            w[u][v] = c;
        }
    }

    for(i=0;i<n;i++)d[i]=INT_MAX;
    d[0] = 0;
    for(i=0;i<n;i++)others.push_back(i);
    for(i=0;i<n;i++)findPath();
    for(i=0;i<n;i++)printf("%d %d\n",i,d[i]);

    return 0;
}

C++: //AOJ ALDS1_12_B dijkstra法 2018/9/20

#include <iostream>
#include <string>
#include <algorithm>
#include <cstdio>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <numeric>
#include <cmath>

using namespace std;

typedef long long int ll;
typedef pair<int, int> P;  //firstは最短距離,secondは頂点番号

#define all(x) x.begin(),x.end()

const ll mod = 1e9+7;
const ll INF = 1e9;
const ll MAXN = 1e9;

struct edge{
	int to,cost;
	edge(){to=0;cost=0;}
};

class dijkstra{
public:
	vector<vector<edge> > E;
	vector<int> dist;
	int start;
	dijkstra(int n): E(n),dist(n){}

	void add_edge(int x,int y,int c){
		edge e;
		e.to = y,e.cost = c;
		E[x].push_back(e);
	}

	void shortest_path(){
		priority_queue<P,vector<P>,greater<P> > que;
		dist.assign(dist.size(),INF);

		dist[start] = 0;
		que.push(P(0,start));

		while(!que.empty()){
			 P p = que.top();
			 que.pop();
			 int v = p.second;
			 if(dist[v] < p.first) continue;

			 for(int i = 0; i < E[v].size(); i++){
			 	edge e = E[v][i];
			 	if(dist[v] +  e.cost < dist[e.to]){
			 		dist[e.to] = dist[v] +  e.cost;
			 		que.push(P(dist[e.to],e.to));
			 	}
			 }
		}
	}


};

int main()
{
	int n;
	cin >> n;
	dijkstra dij(n);
	for(int i = 0; i < n; i++){
		int u,k;
		cin >> u >> k;
		for(int j = 0; j < k; j++){
			int v,c;
			cin >> v >> c;
			dij.add_edge(u,v,c);
		}
	}

	dij.start = 0;
	dij.shortest_path();

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

	return 0;
}

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

using namespace std;
#define rep(i,n) for(int i=0;i<(n);i++)

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

#define MAX 100005
#define INF INT_MAX

struct Edge {
    int to;
    int cost;
};

int main(int, char**)
{
    int n;
    cin >> n;

    vector< vector<Edge> > G(n);
    rep(i,n) {
        int u, k;
        cin >> u >> k;
        rep(j,k) {
            int v, c;
            cin >> v >> c;
            G[u].push_back({v, c});
        }
    }
    priority_queue<P, vector<P>, greater<P> > q;
    vector<int> d(n, INF);
    d[0] = 0;
    q.push({0, 0});
    while (!q.empty()) {
        int v, c;
        tie(c,v) = q.top(); q.pop();
        if (d[v] < c) continue;
        for (auto e : G[v]) {
            if (d[e.to] <= d[v] + e.cost) continue;
            d[e.to] = d[v] + e.cost;
            q.push({d[e.to], e.to});
        }
    }
    rep(i,n) cout << i << " " << d[i] << endl;

    return 0;
}

C++: #include <map>
#include <vector>
#include <cstdio>
using namespace std;
int main(){
	int n=0,N,i,j,k,c;
	scanf("%d",&N);
	vector<map<int,int> >dist(N);
	vector<bool>used(N);
	vector<int>cost(N);
	for(;n<N;n++){
		cost[n]=9999999;
		for(scanf("%d%d",&i,&k);k--;dist[i][j]=c)scanf("%d%d",&j,&c); //i->j cost c
	}
	for(cost[0]=0;;){ //dijkstra
		int m=9999999;
		for(i=0;i<N;i++)if(!used[i]&&m>cost[i])m=cost[i];
		if(m==9999999)break;
		for(j=0;j<N;j++)if(m==cost[j]){
			map<int,int>::iterator it=dist[j].begin();
			for(used[j]=1;it!=dist[j].end();it++)if(cost[it->first]>it->second+cost[j])cost[it->first]=it->second+cost[j];
		}
	}
	for(i=0;i<n;i++)printf("%d %d\n",i,cost[i]);
}