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 <string>
#include <vector>
#include <stdio.h>
#include <math.h>
#include <map>
#include <algorithm>

using namespace std;

#define FAR (1<<22)
#define N 100

static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;


int n, color[N], d[N], p[N];
int m[N][N];

void prim(){
	for (int i = 0; i < n; ++i){
		color[i] = WHITE;
		d[i] = FAR;
		p[i] = -1;
	}

	d[0] = 0;
	int dist = FAR;

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

		if (-1 == u) break;
		color[u] = BLACK;

		for (int v = 0; v < n; ++v){
			if (color[v] != BLACK && (d[u] + m[u][v] < d[v])){
				d[v] = d[u] + m[u][v];
				p[v] = u;
				color[v] = GRAY;
			}
		}
	}
	for (int i = 0; i < n; ++i) cout << i << " " << 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, d; cin >> u >> d;
		for (int j = 0; j < d; ++j) {
			int v, c; cin >> v >> c;
			m[u][v] = c;
		}
	}
 
	prim();

	return 0;
}

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

using namespace std;
typedef long long ll;

// #define DEBUG

const int maxint = 1e9;
struct timestamp;
vector<int> shortest;
vector<vector<pair<int, int>>> connective;

void djkstra(int x)
{
    vector<int> search = {x};
    vector<int> new_search;
    shortest[x] = 0;
    int v, d;
    while (!search.empty())
    {
        for (auto itr = search.begin(); itr != search.end(); itr++)
        {
            for (auto itr2 = connective[*itr].begin(); itr2 != connective[*itr].end(); itr2++)
            {
                v = itr2->first, d = itr2->second;
                if (shortest[v] > d + shortest[*itr])
                {
                    shortest[v] = d + shortest[*itr];
                    new_search.push_back(v);
                }
            }
        }
        search.clear();
        search = new_search;
        new_search.clear();
    }
}

int main()
{

#ifdef DEBUG
    cout << "DEBUG MODE" << endl;
    ifstream in("input.txt"); //for debug
    cin.rdbuf(in.rdbuf());    //for debug
#endif

    int n, v, k, x, c;
    cin >> n;
    connective.resize(n);
    for (int i = 0; i < n; i++)
    {
        cin >> v >> k;
        shortest.push_back(maxint);
        for (int j = 0; j < k; j++)
        {
            cin >> x >> c;
            connective[i].push_back(make_pair(x, c));
        }
    }
    djkstra(0);
    for (int i = 0; i < n; i++)
    {
        cout << i << " " << shortest[i] << endl;
    }

    return 0;
}

// getline(cin,s);
// a = strtok(s, ",");  ","で分解
// for (int i = 0; i < n; i++)
// for (int j = 0; j < m; j++)

C++: #include<iostream>
using namespace std;
static const int MAX =100;
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(color[v]!=BLACK&& M[u][v]!=INFTY){
      if(d[v]>d[u]+M[u][v]){
      d[v]=d[u][v]+M[u][v];

      color[v]=GRAY;
      }
    }
  }
  }
  for(int i=0;i<n;i++){
    cout << i <<" "<<(d[i] == INFTY ? -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] = 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++: #include<bits/stdc++.h>
using namespace std;

typedef pair<int, int> P;
const int M = 1000000007;

vector<int> dijkstra(int s, vector<vector<P>> edge) {
    int n = edge.size();
    vector<int> dist(n, M);
    priority_queue<P, vector<P>, greater<P>> q;
    dist[s] = 0;
    q.push(P(0, s));
    while (!q.empty()) {
        P p = q.top();
        q.pop();
        int d = p.first;
        for (auto& e : edge[p.second]) {
            if (dist[e.second] > p.first + e.first) {
                dist[e.second] = p.first + e.first;
                q.push(P(p.first + e.first, e.second));
            }
        }
    }
    return dist;
}


int main() {
    int n;
    cin >> n;
    vector<vector<P>> edge(n);
    for (int i = 0; i < n; ++i) {
        int u, k;
        cin >> u >> k;
        if (i != u) exit(1);
        for (int j = 0; j < k; ++j) {
            int v, c;
            cin >> v >> c;
            edge[i].push_back(P(c, v));
        }
    }
    vector<int> d = dijkstra(0, edge);
    for (int i = 0; i < n; ++i) {
        cout << i << " " << d[i] << "\n";
    }
    return 0;
}

C++: #include<iostream>
using namespace std;
#define N 105
#define INF 1<<21
int n;
int a[N][N];
int d[N],p[N];
int color[N];
void dijksla(){
	int minv;
	for (int i = 0;i < n;i++){
		d[i] = INF;
		color[i] = 0;
	}
	d[0] = 0;
	while (1){
		minv = INF;
		int u = -1;
		for (int i = 0;i < n;i++){
			if (minv > d[i] && color[i] != 1){
				u = i;
				minv = d[i];
			}
		}
		if (u == -1) break;
		color[u] = 1;
		for (int v = 0;v < n;v++){
			if (color[v] == 0 && a[u][v] != INF){
				if (d[v] > d[u] + a[u][v]){
					d[v] = d[u] + a[u][v];
				}
			}
		}
	}
	for (int i = 0;i < n;i++){
		if (d[i] == INF){
			cout << i << " -1" << endl;
		}
		else{
			cout << i << " " << d[i] << endl;
		}
	}
}

int main()
{
	cin >> n;
	for (int i = 0;i < n;i++){
		for (int j = 0;j < n;j++){
			a[i][j] = INF;
		}
	} 
	int x,m,y,q;
	for (int i = 0;i < n ;i++){
		cin >> x >> m;
		for (int j = 0;j < m;j++){
			cin >> y >> q;
			a[x][y] = q;
		}
	}
	dijksla();
	return 0;
 }