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>

using namespace std;

#define INT_MIN     (-2147483647 - 1) /* minimum (signed) int value */
#define INT_MAX       2147483647    /* maximum (signed) int value */
static const int MAX = 100;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n, m[MAX][MAX];

int prim()
{
	int color[MAX], p[MAX], d[MAX];
	int u, minv;

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

	d[0] = 0;

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

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

		for (int i = 0; i < n; ++i)
		{
			if (m[u][i] < d[i] && color[i] != BLACK)
			{
				d[i] = m[u][i];
				p[i] = u;
				color[i] = GRAY;
			}
		}
	}

	int sum = 0;
	for (int i = 0; i < n; ++i)
	{
		if (p[i] != -1)
			sum += m[p[i]][i];
	}
	return sum;
}

void dijkstra()
{
	int minv;
	int d[MAX], color[MAX];

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

	d[0] = 0;
	color[0] = GRAY;

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

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

		for (int i = 0; i < n; ++i)
		{
			if (color[i] != BLACK && m[u][i] + d[u] < d[i])
			{
				d[i] = d[u] + m[u][i];
				color[i] = GRAY;
			}
		}
	}

	for (int i = 0; i < n; ++i)
		cout << i << " " << ((d[i] == INT_MAX) ? -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] = MAX;
		}
	}

	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>
#define rep(i,n) for (int i = 0; i < (n); ++i)
using namespace std;
typedef long long ll;

int M[200][200];
string color[200];
int d[200];
int p[200];
int n;
const int INF = 1001001001;

void dijkstra(int s){
    rep(i, n){
        color[i] = "WHITE";
        d[i] = INF;
    }
    d[s] = 0;
    p[s] = -1;

    int u;
    while(true){
        int mincost = INF;
        for (int i = 0; i < n; i++){
            if(color[i] != "BLACK" && d[i] < mincost){
                mincost = d[i];
                u = i;
            }
        }
        if(mincost == INF){
            break;
        }
        color[u] = "BLACK";
        
        for (int v = 0; v < n; v++){
            if(color[v] != "BLACK" && M[u][v] != INF){
                if(d[u] + M[u][v] < d[v]){
                    d[v] = d[u] + M[u][v];
                    p[v] = u;
                    color[v] = "GRAY";
                }
            }
        }
    }
}

int main() {
    cin >> n;
    rep(i, n){
        rep(j, n){
            M[i][j] = INF;
        }
    }
    rep(i, n){
        int u; cin >> u;
        int k; cin >> k;
        rep(j, k){
            int c, v; cin >> c >> v;
            M[u][c] = v;
        }
    }
    dijkstra(0);
    rep(i, n){
        cout << i << " " << d[i] << endl;
    }

    return 0;
}

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

using namespace std;
const int INF = 1001001001;

void djkstra(const vector< vector< int > >& edges, vector< int >& d, int root)
{
    int n = d.size(), node, min_dist;
    d[root] = 0;
    vector<int> color(n, 0);

    while(true)
    {
        min_dist = INF;
        for(int i=0;i<n;++i)
        {
            if(color[i] == 0 && d[i] < min_dist)
            {
                node = i;
                min_dist = d[i];
            }
        }
        if(min_dist == INF) break;
        color[node] = 1;
        for(int i=0;i<n;++i)
        {
            d[i] = min(d[i], edges[node][i] + d[node]);
        }
    }
}

int main()
{
    int n, k, u, v, c;
    cin >> n;
    vector< vector< int > > edges(n, vector<int>(n, INF));
    vector<int> d(n, INF);
    for(int i=0;i<n;++i)
    {
        cin >> u >> k;
        for(int j=0;j<k;++j)
        {
            cin >> v >> c;
            edges[u][v] = c;
        }
    }

    djkstra(edges, d, 0);
    for(int i=0;i<d.size();++i)
    {
        cout << i << " " << d[i] << endl;
    }
}

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

using namespace std;

#define FOR(i,s,e) for((i)=(s);(i)<(int)(e);(i)++)
#define REP(i,e) FOR(i,0,e)

#define all(o) (o).begin(), (o).end()
#define psb(x) push_back(x)
#define mp(x,y) make_pair((x),(y))

typedef long long ll;
typedef pair<int, int> PII;

const double EPS = 1e-10;

const int INF = 1000 * 1000 * 10;
const int N = 100;
int d[N][N];
int n;

int main() {
  int i, j, k;
  int u, v, c; 

  scanf("%d ", &n);
  for (i=0; i<n; i++) 
    for (j=0; j<n; j++) {
      if (i==j)
        d[i][j] = 0;
      else
        d[i][j] = INF;
    }

  for (i=0; i<n; i++) {
    scanf("%d%d ", &u, &k);
    for (j=0; j<k; j++) {
      scanf("%d%d ", &v, &c);
      d[u][v] = c;
    }
  }

  //Warshall-Floyd
  for (k=0; k<n; k++)
    for (i=0; i<n; i++)
      for (j=0; j<n; j++)
        d[i][j] = min(d[i][j], d[i][k] + d[k][j]);

  for (i=0; i<n; i++) {
    printf("%d %d\n", i, d[0][i]); 
  }

	return 0;
}