Go: package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
	"strconv"
)

const NIL = -1

type Node struct {
	id     int
	weight int
}

func init() {
	sc.Split(bufio.ScanWords)
}

type NodeHeap []Node

func (h NodeHeap) Len() int           { return len(h) }
func (h NodeHeap) Less(i, j int) bool { return h[i].weight < h[j].weight }
func (h NodeHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *NodeHeap) Push(x interface{}) {
	*h = append(*h, x.(Node))
}

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

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func main() {
	n := scanInt()

	list := make([][]int, n)
	weight := make([]int, n)
	for i := range list {
		list[i] = make([]int, n)
		weight[i] = NIL
		for j := range list[i] {
			list[i][j] = NIL
		}
	}

	for i := 0; i < n; i++ {
		u := scanInt()
		k := scanInt()
		for j := 0; j < k; j++ {
			v := scanInt()
			w := scanInt()
			list[u][v] = w
		}
	}

	start := Node{id: 0, weight: 0}
	h := &NodeHeap{start}
	heap.Init(h)

	for h.Len() > 0 {
		node := heap.Pop(h).(Node)
		if weight[node.id] != NIL {
			continue
		}
		weight[node.id] = node.weight

		for i, w := range list[node.id] {
			if w == NIL {
				continue
			}
			heap.Push(h, Node{id: i, weight: w + node.weight})
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		fmt.Fprint(w, i)
		fmt.Fprint(w, " ")
		fmt.Fprint(w, weight[i])
		fmt.Fprintln(w)
	}
	w.Flush()
}

C++: #include<iostream>
#include<vector>
#include<queue>
#define INF 2e9
using namespace std;

void Dikstra(const vector<vector<pair<int, int> > >& G, vector<int>& d){
    d[0] = 0;
    priority_queue<pair<int, int> , vector<pair<int, int> >, greater<pair<int, int> > > PQ;
    PQ.push(make_pair(0, 0));
    vector<bool> is_black(d.size(), false);
    is_black[0] = true;
    while (!PQ.empty()) {
        int t = PQ.top().second;
        PQ.pop();
        is_black[t] = true;
        for (int i = 0; i < G[t].size(); i++) {
            int v = G[t][i].first;
            int w = G[t][i].second;
            if (!is_black[v] && d[t] + w < d[v]) {
                d[v] = d[t] + w;
                PQ.push(make_pair(d[v], v));
            }
        }
    }

}

int main(){
    int n;
    cin >> n;
    vector<vector<pair<int, int> > > G(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;
            G[u].push_back(make_pair(v, c));
        }
    }
    vector<int> d(n, INF);
    Dikstra(G, d);
    for (int i = 0; i < n; i++) {
       cout << i << " " << d[i] << endl;
    }

    return 0;
}

C++: #include <iostream>
#include <vector>
#include <queue>

#define INF 1000000000
using namespace std;

struct edge {
    int from;
    int to;
    int w;
};
struct node {
    node() : id {-1}, d {INF}, ns {} {};
    node(int i, vector<edge>& vec) : id {i}, d {INF}, ns {vec} {};
    int id;
    int d;
    vector<edge> ns;
};

vector<int> dijkstra(node* graph, int n, int st){
    auto ds = vector<int>(n, INF);
    auto comp = [](node* x, node* y){return x->d > y->d;};
    priority_queue<node*, vector<node*>, decltype(comp)> que(comp);
    node* start = &graph[st];
    start->d = 0;
    que.push(start);
    while(que.size()){
        node* n = que.top();
        //cout << n->id << ' ' << n->d << endl;
        que.pop();
        if(n->d < ds[n->id]){
            ds[n->id] = n->d;
            for(auto e : n->ns){
                node* next_n = &graph[e.to];
                if(ds[next_n->id] < INF){
                    continue;
                }
                next_n->d = min(next_n->d, n->d + e.w);
                que.push(next_n);
            }
        }
    }
    return ds;
}

int main(){
    cin.sync_with_stdio(false);
    cout.sync_with_stdio(false);
    int n;
    cin >> n;
    node graph[n];
    for(int i = 0; i < n; ++i){
        int id;
        int m;
        cin >> id >> m;
        auto vec = vector<edge>(m);
        int v, c;
        for(int j = 0; j < m; ++j){
            cin >> v >> c;
            vec[j] = edge {id, v, c};
        }
        graph[id] = node(id, vec);
    }
    auto ds = dijkstra(graph, n, 0);
    for(int i = 0; i < n; ++i){
        cout << i << ' ' << ds[i] << endl;
    }
}

C++: #include<iostream>
using namespace std;
#define INF 1000000
int m[100][100]; //adjacency matrix
int n; //vertexes
void dijkstra();
int main() {
    cin >> n;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            m[i][j] = INF;
        }
    }
    for (int i = 0; i < n; i++) {
        int u; //number
        int k; //output orders
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            int v; //vertex
            int c; //weight
            cin >> v >> c;
            m[u][v] = c;
        }
    }
    dijkstra();
    return 0;
}
void dijkstra() {
    int d[100]; //minimum cost
    int p[100]; //top parent
    d[0] = 0;
    p[0] = 1;
    for (int i = 1; i < n; i++) {
        p[i] = 0;
        d[i] = INF;
    }
    while (1) {
        int minv = INF;
        int u = -1;
        for (int i = 0; i < n; i++) {
            if (minv > d[i] && p[i] != 2) { //firstly only d[0]
                u = i; //tmp parent
                minv = d[i]; //min cost of 0 to i
            }
        }
        if (u == -1) {
            break;
        }
        p[u] = 2; //決まったら
        for (int v = 0; v < n; v++) {
            if (m[u][v] != INF && p[v] != 2) { //u and v are connected
                if (d[v] > d[u] + m[u][v]) {
                    d[v] = d[u] + m[u][v]; //get smaller cost
                    //ここでd[v]がINFから解放され、次の親になれる
                    p[v] = 1;
                }
            }
        }
    }
    for (int i = 0; i < n; i++) {
        cout << i << " ";
        if (d[i] == INF) {
            cout << -1 << endl;
        } else {
            cout << d[i] << endl;
        }
    }
}

C++: //
//  main.cpp
//  minnimum_spanning_tree
//
//  Created by ???????????? on 2017/10/23.
//  Copyright ?? 2017 ????????????. All rights reserved.
//

#include <iostream>
#include <stdio.h>

#define n_max 100
#define WHITE 0
#define GRAY 1
#define BLACK 2
#define INFTY 3000

using namespace std;

int n, M[n_max][n_max], color[n_max], d[n_max], p[n_max];

void init(){
    int i, j, id, num, node;
    scanf("%d", &n);
    for(i = 0; i < n; i++){
        for(j = 0; j < n; j++){
            M[i][j] = INFTY;
        }
    }
    
    
    for(i = 0; i < n; i++){
        scanf("%d %d", &id, &num);
        for(j = 0; j < num; j++){
            scanf("%d", &node);
            scanf("%d", &M[id][node]);
        }
        color[i] = WHITE;
        d[i] = INFTY;
    }
}

void dijkstra(){
    //initializing
    d[0] = 0;
    p[0] = -1;
    
    int u;
    while(true){
        int mincost = INFTY;
        for(int i = 0; i < n; i++ ){
            if((color[i] != BLACK) && (d[i] < mincost)){
                mincost = d[i];
                u = i;
            }
        }
        
        if (mincost == INFTY) break;
        
        color[u] = BLACK;
        
        for(int v = 0; v < n; v++){
            if((color[v] != BLACK) && (M[u][v] != INFTY)){
                if((d[u] + M[u][v]) < d[v]){
                    d[v] = M[u][v] + d[u];
                    p[v] = u;
                    color[v] = GRAY;
                }
            }
        }
    }
    for(int i = 0; i < n; i++){
        cout<<i<<" "<<d[i]<<endl;
    }
}

int main(int argc, const char * argv[]) {
    init();
    dijkstra();
    //    std::cout << "Hello, World!\n";
    return 0;
}