Go: package main

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

type Item struct {
	value    int // The value of the item; arbitrary.
	priority int // The priority of the item in the queue.
	// The index is needed by update and is maintained by the heap.Interface methods.
	index int // The index of the item in the heap.
}
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }
func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].priority < pq[j].priority
}
func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = i
	pq[j].index = j
}
func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}
func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	item.index = -1 // for safety
	*pq = old[0 : n-1]
	return item
}

type Q struct {
	pq *PriorityQueue
	ds map[int]int // It has always same value as pq. For random access.
}

func newQ() *Q {
	pq := new(PriorityQueue)
	heap.Init(pq)
	return &Q{
		pq: pq,
		ds: make(map[int]int),
	}
}
func (q *Q) pop() (u, d int) {
	item := heap.Pop(q.pq).(*Item)
	delete(q.ds, item.value)
	return item.value, item.priority
}
func (q *Q) get(u int) (int, bool) { // returns d
	d, ok := q.ds[u]
	return d, ok
}
func (q *Q) set(u, d int) {
	q.ds[u] = d
	for _, item := range *q.pq {
		if item.value != u {
			continue
		}

		item.priority = d
		heap.Fix(q.pq, item.index)
		return
	}
	heap.Push(q.pq, &Item{
		priority: d,
		value:    u,
	})
}
func (q *Q) len() int {
	return len(q.ds)
}

func main() {
	r := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(r, &n)
	cs := make([]map[int]int, n) // []v_i -> c_i
	for h := 0; h < n; h++ {
		var u, k int
		fmt.Fscan(r, &u, &k)
		m := make(map[int]int)
		for i := 0; i < k; i++ {
			var v, c int
			fmt.Fscan(r, &v, &c)
			m[v] = c
		}

		cs[u] = m
	}

	q := newQ()
	q.set(0, 0)
	visited := make(map[int]struct{})
	out := make([]int, n)

	for q.len() > 0 {
		u, d := q.pop()
		for uu, c := range cs[u] {
			// Consider the connection between u and uu.
			if _, ok := visited[uu]; ok {
				continue
			}
			dd := d + c
			if d, ok := q.get(uu); !ok || d > dd {
				q.set(uu, dd)
			}
		}

		out[u] = d
		visited[u] = struct{}{}
	}

	for u, d := range out {
		fmt.Println(u, d)
	}
}

C++: #include<iostream>
#include<algorithm>
#include<stdio.h>
using namespace std;

static const int INFTY = (1<<21);
enum Color{
    WHITE,
    GRAY,
    BLACK
};
int n;

int M[100][100];
Color color[100];
int d[100];

void dijkstra(){
    for(int i=0; i<n; i++){
        d[i] = INFTY;
        color[i] = WHITE;
    }

    d[0] = 0;
    color[0] = GRAY;
    int minv;
    while(true){
        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(color[v]!=BLACK && M[u][v]!=INFTY){
                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++){
            printf("%d ", i);
            if(d[i]==INFTY) printf("-1");
            else printf("%d", d[i]);
            printf("\n");
        }
}

int main(){

    scanf("%d", &n);

    for(int i=0; i<n; i++){
        for(int j=0; j<n; j++){
            M[i][j] = INFTY;
        }
    }
    int u, k;
    for(int j=0; j<n; j++){
    cin >> u >> k;
    for(int i=0; i<k; i++){
        int v, c;
        cin >> v >> c;
        M[u][v] = c;
    }
    }

    dijkstra();

    return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, n) for(int i = 0; i < (n); i++)
using namespace std;
using ll = long long;

constexpr int LEN = 105;
int a[LEN][LEN];

int dikstra(int g, const int n){
	int d[n];
	bool check[n] = {0};
	memset(d, 1, sizeof(d));
	d[0] = 0;

	while(true){
		int u;
		int min_cost = INT_MAX;
		rep(i, n){
			if(!check[i] && (d[i] < min_cost)) {
				min_cost = d[i];
				u = i;
			}
		}

		if(min_cost == INT_MAX) break;
		check[u] = true;

		rep(v, n){
			if(!check[v] && (a[u][v] > -1)){
				if((d[u] + a[u][v]) < d[v]){
					d[v] = d[u] + a[u][v];
				}
			}
		}
	}

	return d[g];
}

int main(){
	memset(a, -1, sizeof(a));
	int n; cin >> n;
	rep(i, n){
		int u, k; cin >> u >> k;
		rep(j, k){
			int v, c; cin >> v >> c;
			a[u][v] = c;
		}
	}

	rep(i, n) cout << i << ' ' << dikstra(i, n) << endl;

	return 0;
}

C++: import java.util.ArrayList;
import java.util.Arrays;
import java.util.PriorityQueue;
import java.util.Scanner;

public class Main {
    int[] distTo = null;
    int[] parentOf = null;

    public Dijkstra(ArrayList<ArrayList<Edge>> G){
        distTo = new int[G.size()];
        Arrays.fill(distTo, Integer.MAX_VALUE);
        parentOf = new int[G.size()];

        PriorityQueue<SDto> pq = new PriorityQueue<>();

        pq.add(new SDto(0, 0, -1));
        while (!pq.isEmpty()) {

            SDto optim = pq.poll();

            if (optim.d < distTo[optim.v]) {
                distTo[optim.v] = optim.d;
                parentOf[optim.v] = optim.from;
                for (Edge e : G.get(optim.v)) {
                    if (optim.from != e.v) { // prevent go back
                        pq.add(new SDto(e.v, distTo[optim.v] + e.c, optim.v));
                    }
                }

            }
        }

    }

    private static class SDto implements Comparable<SDto> { // Shortest distance to vertex
        int v, d, from;

        SDto(int v, int d, int from) {
            this.v = v;
            this.d = d;
            this.from = from;
        }

        @Override
        public int compareTo(SDto that) {
            if(this.d > that.d) return 1;
            else if(this.d < that.d) return -1;
            return 0;
        }


    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);

        int n = in.nextInt();

        ArrayList<ArrayList<Edge>> G = new ArrayList<>(n);
        for (int i = 0; i < n; i++) {
            G.add(new ArrayList<>());
        }

        for (int i = 0; i < n; i++) {
            int u = in.nextInt();
            int k = in.nextInt();
            for (int j = 0; j < k; j++) {
                int v = in.nextInt(), c = in.nextInt();
                G.get(i).add(new Edge(v, c));
                G.get(v).add(new Edge(i, c));
            }
        }

        Main dijkstra = new Main(G);

        for (int i = 0; i < G.size(); i++) {
            System.out.printf("%d %d\n", i, dijkstra.distTo[i]);
        }
    }
}

class Edge {
    int v, c;

    Edge(int v, int c) {
        this.v = v;
        this.c = c;
    }

    @Override
    public String toString() {
        return String.format("(v=%d, c=%d)", v, c);
    }
}

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

using namespace std;

static const long long FAR = (1LL << 21);
static const int N = 100;

int n, m[N][N];
bool visited[N];
int d[N], p[N];

void dijskra(){
	for (int i = 0; i < n; ++i) {
		d[i] = FAR;
		visited[i] = false;
	}

	d[0] = 0;
	while (true) {
		int mi = FAR;
		int u = -1;
		for (int i = 0; i < n; ++i) {
			if (!visited[i] && d[i] < mi){
				u = i;
				mi = d[i];
			}
		}

		if (-1 == u) break;
		visited[u] = true;

		for (int v = 0; v < n; ++v) {
			if (!visited[v] && (m[u][v] != FAR) && (d[u] + m[u][v] < d[v])) {
				d[v] = d[u] + m[u][v];
			}
		}
	}

	for (int i = 0; i < n; ++i)
		cout << i << " " << ((d[i] == FAR) ? -1 : d[i]) << endl;
}

int main()
{
	cin >> n;
	for (int i = 0; i < n; ++i){
		for (int j = 0; j < n; ++j) m[i][j] = FAR;
	}

	for (int i = 0; i < n; ++i) {
		int u, k; cin >> u >> k;
		for (int j = 0; j < k; ++j)	{
			int v, e; cin >> v >> e;
			m[u][v] = e;
		}
	}
	dijskra();

	return 0;
}