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>
using namespace std;
typedef pair<int, int> P;
static const int Maxn = 10010;
static const int INFTY = (1 << 21);
static const int WHITE = 0;
static const int BLACK = 1;
vector <P> a[Maxn];
int n, d[Maxn], p[Maxn], color[Maxn];
struct cmp{
	bool operator()(P x, P y){
		return x.first > y.first;
	}
		
};
void dijkstra();
int main()
{
	int u, k, c, v;
	cin >> n;
	for(int i = 0; i < n; i++){
		cin >> u >> k;
		while(k--){
			cin >> v >> c;
			a[u].push_back(make_pair(v, c));
		}
	}
	dijkstra();
	return 0;
}
void dijkstra(){
	priority_queue <P, vector<P>, cmp> q;
	for(int i = 0; i < n; i++){
		d[i] = INFTY;
		color[i] = WHITE;
	} 
	d[0] = 0;
	q.push(make_pair(0,0));
	while(!q.empty()){
		P f = q.top(); q.pop();
		//printf("%d %d\n", f.first, f.second);
		int u = f.second;
		color[u] = BLACK;
		if(d[u] > f.first) continue;
		for(int i = 0; i < a[u].size(); i++){
			int v = a[u][i].first;
			if(color[v] == BLACK) continue;
			if(d[v] > d[u] + a[u][i].second){//
				d[v] = d[u] + a[u][i].second;
				q.push(P(d[v], v));
			} 
		}
	}
	for(int i = 0; i < n; i++) cout << i << ' ' << d[i] << endl;
}

C++: #include<iostream>
using namespace std;

static const int MAX = 1000;
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 (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(int argc, char const* argv[])
{
    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++: // ALDS1_12_C.cpp
// Graph II - Single Source Shortest Path II
#include <iostream>
#include <vector>
#include <algorithm>
#include <cstdio>
using namespace std;

struct Node {
    int v;
    int c;
    Node(int v, int c): v(v), c(c) {}
};

const int maxN = 100;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;
static const int INF = (1<<21);
vector<Node> G[maxN];
vector<int> dist(maxN, INF);
vector<int> p(maxN);
vector<int> color(maxN, WHITE);
int n;
int cnt = 0;
void dijkstra(int x)
{
    dist[x] = 0;
    p[x] = -1;
    while(++cnt != n) {
        int u = 0;
        int mindist = INF;
        for (int i = 0; i < n; i++) {
            if (color[i] != BLACK && dist[i] < mindist) {
                mindist = dist[i];
                u = i;
            }
        }

        for (int i = 0; i < G[u].size(); i++) {
            if (color[u] == BLACK) continue;
            int v = G[u][i].v;
            int c = G[u][i].c;
            if (dist[u] + c < dist[v]) {
                dist[v] = dist[u] + c;
                p[v] = u;
                color[v] = GRAY;
            }
        }
        color[u] = BLACK;
    }
}

int main()
{
    cin >> n;
    int u, k;
    int v, c;
    for (int i = 0; i < n; i++) {
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            cin >> v >> c;
            G[i].push_back(Node(v, c));
        }
    }
    dijkstra(0);
    for (int i = 0; i < n; i++) {
        printf("%d %d\n", i, dist[i]);
    }
    return 0;
}