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 <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;
}

C++: #include <iostream>
#include <algorithm>
#include <stack>
#include <queue>
#include <vector>
#include <map>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>

using namespace std;

#define MAX_N 100
#define INF 100000 * 100 + 1

int cost[MAX_N][MAX_N];
int d[MAX_N];
bool used[MAX_N];
int V;

void dijkstra(int s) {
	fill_n(d, V, INF);
	fill_n(used, V, false);
	d[s] = 0;

	while (1) {
		int v = -1;
		for (int u = 0; u < V; u++)
			if (!used[u] && (v == -1 || d[u] < d[v]))
				v = u;

		if (v == -1)
			break;

		used[v] = true;

		for (int u = 0; u < V; u++)
			d[u] = min(d[u], d[v] + cost[v][u]);
	}
}

int main() {
	int n;
	cin >> n;
	V = n;
	for (int i = 0; i < n; i++) {
		int u, k;
		cin >> u >> k;
		fill_n(cost[u], n, INF);
		for (int j = 0; j < k; j++) {
			int v, c;
			cin >> v >> c;
			cost[u][v] = c;
		}
	}
	dijkstra(0);
	for (int i = 0; i < n; i++) {
		cout << i << " " << d[i] << endl;
	}
	
	return 0;
}

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]+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<iostream>
int main(){
  int u,k,C,V,D[1000][1000],n;
  std::cin >> n;
  for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j] = 200001;
  for(int i=0;i<n;i++){     std::cin >> u >> k;
    for(int j=0;j<k;j++){   std::cin >> V >> C;
      D[u][V] = C;}}
  for(int i=0;i<n;i++)D[i][i] = 0;
  for(int k=0;k<n;k++)for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j]= std::min(D[i][j],D[i][k] + D[k][j]);
  for(int i=0;i<n;i++)std::cout << i << " " << D[0][i] << std::endl;
  return 0;
}

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

using namespace std;

class Node {
public:
	int p, d = -1;
};

class Edge {
public:
	int v, u, d;
};

int n, V[100], e = 0;
Edge E[5000];

void Path() {
	V[0] = 0; for (int i = 1; i < n; i++)  V[i] = -1;
	for (int a = 1; a < e; a++) {
		for (int i = 0; i < e; i++) {
			if (V[E[i].u] == -1 && V[E[i].v] != -1 || V[E[i].u] > V[E[i].v] + E[i].d && V[E[i].v] != -1) {
				V[E[i].u] = V[E[i].v] + E[i].d;
			}
		}
	}
}

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

	Path();

	for (int i = 0; i < n; i++) cout << i << " " << V[i] << endl;
}

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

#define MAX_VERTEX 100
#define INF 1000000

int vertex_num; // ???????????°
int d[MAX_VERTEX][MAX_VERTEX];  // ???????????¢???d[?§????][??????]??§?§??????????????????????????????¢?????¨???

void Input() {
  cin >> vertex_num;

  // (a1) ??\???????????¶??§?????????
  // d?????¨???INF?????????????§??????¨????????????????????´???0
  for (int i = 0; i < vertex_num; i++){
	  for (int j = 0; j < vertex_num; j++){
		  if(i==j){
		  	d[i][j]=0;
		  	}else{
		  	d[i][j]=INF;
		  	}
	  }
  }

  for (int i = 0; i < vertex_num; i++) {
    int vertex, out;
    cin >> vertex >> out;
    for(int j = 0; j < out; j++) {
      int to, c;
      cin >> to >> c;
      d[vertex][to] = c;
    }
  }
}

void WarshallFloyd() {
	// (b1)?§£??¬?????????????????????
	for (int k = 0; k < vertex_num; k++){
		for (int i = 0; i < vertex_num; i++){
			for (int j = 0; j < vertex_num; j++){
				d[i][j] = min(d[i][j],d[i][k]+d[k][j]);
			}
		}

	}
}

void Output() {
  for(int i = 0; i < vertex_num; i++) {
    cout << i << " " << d[0][i] << endl;
  }
}

int main() {

  Input();
  WarshallFloyd();
  Output();

  return 0;
}