Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)

	g := makeGraph(n)
	for i := 0; i < n; i++ {
		u := getNextInt(scanner)
		k := getNextInt(scanner)
		for ii := 0; ii < k; ii++ {
			v := getNextInt(scanner)
			c := getNextInt(scanner)
			g[u][v] = c
		}
	}

	ans := make([]int, n)
	im := make(IntMap, 1)
	im.increment(0)
	for len(im) < n {
		min := 1 << 30
		x := -1
		for u := range im {
			for v := 0; v < n; v++ {
				if im.get(v) != 0 {
					continue
				}
				if min > ans[u]+g[u][v] {
					min = ans[u] + g[u][v]
					x = v
				}
			}
		}
		im.increment(x)
		ans[x] = min
	}

	for i := 0; i < n; i++ {
		fmt.Fprintln(writer, fmt.Sprintf("%d %d", i, ans[i]))
	}
	writer.Flush()
}

func makeGraph(n int) [][]int {
	g := make([][]int, n)
	for i := 0; i < n; i++ {
		g[i] = make([]int, n)
		for ii := 0; ii < n; ii++ {
			g[i][ii] = 1 << 30
		}
	}

	return g
}

// IntMap ...
type IntMap map[int]int

func (m IntMap) get(key int) int {
	if _, ok := m[key]; ok {
		return m[key]
	}
	return 0
}
func (m IntMap) increment(key int) {
	if _, ok := m[key]; ok == false {
		m[key] = 0
	}
	m[key]++
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <string>
#include <cmath>
#include <vector>
#include <queue>
#include <climits>
typedef long long ll;
using namespace std;

struct Dijkstra{
  int n,i;
  vector<vector<pair<int,int> > > edge; //cost,to
  vector<int> distance;
  vector<int> prev;

  void init(int v){
    n=v;
    edge.resize(n);
    distance.resize(n);
    prev.resize(n);
  }

  void calc(int start){
    for(i=0;i<n;i++){
      distance[i]=INT_MAX;
      prev[i]=-1;
    }
    distance[start]=0;

    priority_queue<pair<int,int> > q; //cost,to
    int from,to,tmp;
    q.push({0,start});

    while(!q.empty()){
      from=q.top().second;
      q.pop();
      for(i=0;i<edge[from].size();i++){
        int to=edge[from][i].second;
        int tmp=distance[from]+edge[from][i].first;
        if(distance[to]>tmp){
          distance[to]=tmp;
          prev[to]=from;
          q.push({tmp,to});
        }
      }
    }

  }
};

int main(void){
  int n,u,k,v,c,i,j;
  Dijkstra graph;
  cin>>n;
  graph.init(n);
  for(i=0;i<n;i++){
    cin>>u>>k;
    for(j=0;j<k;j++){
      cin>>v>>c;
      graph.edge[u].push_back({c,v});
    }
  }
  graph.calc(0);

  for(i=0;i<n;i++){
    cout<<i<<" "<<graph.distance[i]<<endl;
  }

  return 0;
}

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);
    }
}