Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
type Node struct {
	cost int
	done bool
}

type Edge struct {
	to, cost int
}

const INF = 1 << 60

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	nodes := make([]Node, N)
	for i := 0; i < N; i++ {
		nodes[i].cost = INF
	}
	E := make([][]Edge, N)
	for i := 0; i < N; i++ {
		id, k := sc.nextInt(), sc.nextInt()
		for j := 0; j < k; j++ {
			to, cost := sc.nextInt(), sc.nextInt()
			E[id] = append(E[id], Edge{to, cost})
		}
	}
	nodes[0].cost = 0
	for {
		cur := 0
		minCost := INF
		for i := 0; i < N; i++ {
			n := nodes[i]
			if !n.done && n.cost < minCost {
				cur = i
				minCost = n.cost
			}
		}
		if minCost == INF {
			break
		}
		nodes[cur].done = true
		for i := 0; i < len(E[cur]); i++ {
			to, cost := E[cur][i].to, E[cur][i].cost+nodes[cur].cost
			if !nodes[to].done && cost < nodes[to].cost {
				nodes[to].cost = cost
			}
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i, nodes[i].cost)
	}
	wtr.Flush()
}

C++: #include <iostream>
using namespace std;
static const int SIZE = 100;
static const int INF = 1e9+7;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;
static const int NIL = -1;

int n;
int G[SIZE][SIZE],d[SIZE];

void dijkstra(){
    int u,mincost;
    int color[SIZE];

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

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

    while(1){
        mincost = INF;
        u = NIL;

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

        if(u == NIL) break;

        color[u] = BLACK;

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

int main(){
    cin>>n;

    for(int i=0; i<n; i++){
        for(int j=0; j<n; j++){
            G[i][j] = INF;
        }
    }

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

    dijkstra();

    for(int i=0; i<n; i++){
        cout<<i<<" ";
        if(d[i] != INF) cout<<d[i]<<endl;
        else cout<<-1<<endl;
    }

    return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <string>
#include <list>
#include <stack>
#include <queue>
#include <algorithm>
#include <utility>
#include <vector>
#include <map>
#include <bitset>

using namespace std;

int main()
{
	int N;
	cin>>N;
	bitset<100> data(1);
	
	vector<vector<int> > cost(N,vector<int>(N,100001));
	cost[0][0]=0;
	pair<int,int> ddata;
	for(int i=0;i<N;i++){
		int u,k;
		cin>>u>>k;
		for(int j=0;j<k;j++){
			cin>>ddata.first>>ddata.second;
			cost[u][ddata.first]=ddata.second;
		}
	}
	//
	int n;
	for(int i=0;data.count()<N;i=n){
		n=1;
		for(int j=1;j<N;j++){
			if(data[j]){
				continue;
			}//*/
			if(i!=j&&cost[0][j]>cost[0][i]+cost[i][j]){
				cost[0][j]=cost[0][i]+cost[i][j];
			}
			if(data[n]||cost[i][j]<cost[i][n]){
				n=j;
			}
		}
		data.set(n);
	}
	for(int i=0;i<N;i++){
		cout<<i<<' '<<cost[0][i]<<endl;
	}
	return 0;
}

C++: #include<stdio.h>
#define MAX 100
#define INFTY 2097152
#define WHITE 0
#define GRAY 1
#define BLACK 2
void dijkstra();
int n,M[MAX][MAX];

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

  dijkstra();
  return 0;}

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++){
 
    printf("%d ",i);
    if(d[i]==INFTY)
      printf("%d",-1);
    else
      printf("%d",d[i]);
 printf("\n");
  }}

C++: #include<iostream>

using namespace std;

#define MAX 100

#define WHITE 0
#define GRAY 1
#define BLACK 2
#define INFTY 1<<21

int n;
int color[MAX],p[MAX],d[MAX],M[MAX][MAX];

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

  d[0] = 0;
  p[0] = -1;
  color[0] = GRAY;

  while(true){

    int minicost = INFTY;
    int u=-1;

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

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

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

}


int main(void){
  cin >> n;
  int u,k;
  int s, t;

  for(int i=0;i<n;i++){
    for(int j=0;j<n;j++){
      M[i][j] = INFTY;
    }
  }

  for(int i=0;i<n;i++){
    cin >> u >> k;
    for(int j=0;j<k;j++){
      cin >> s >> t;
      M[u][s] = t;  
    }
  }

  dijkstra();

  return 0;
}