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>
#include <utility>
#include <vector>
#include <climits>
using namespace std;

static const int MAX_N = 100;

void dijkstra(vector<vector<pair<int, int> > > way)
{
    int d[way.size()];
    bool on[way.size()];
    for (int i = 0; i < way.size(); i++) {
        d[i] = INT_MAX;
        on[i] = false;
    }
    d[0] = 0;
    while (1) {
//        cout << "d:";
//        for (int i = 0; i < way.size(); i++) {
//            cout << " " << d[i];
//        }
//        cout << endl;
        int u, minv = INT_MAX;
        for (int i = 0; i < way.size(); i++) {
            if (minv > d[i] && !on[i]) {
                minv = d[i];
                u = i;
            }
        }
        if (minv == INT_MAX) break;
        on[u] = true;
        for (auto itr = way.at(u).begin(); itr != way.at(u).end(); ++itr) {
            if (!on[itr->first]) {
                d[itr->first] = min(d[itr->first], d[u] + itr->second);
            }
        }
    }
    for (int i = 0; i < way.size(); i++) {
        cout << i << " " << d[i] << endl;
    }
}

int main()
{
    int n;
    cin >> n;
    vector<vector<pair<int, int> > > way(n);
    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;
            way.at(u).push_back(make_pair(v, c));
        }
    }
    dijkstra(way);
    return 0;
}

C++: #include<bits/stdc++.h>
#define ll long long
using namespace std;
const int INF = 0x3f3f3f;
int a[300][300];
int vis[300];	//标记是否访问过 
int path[300];	//从起点到该点的距离 
int n;
void Dijkstra(int s)
{
	int min,pos;
	
	memset(vis,0,sizeof(vis));
	
	path[s] = 0;
	vis[s]  = 1;
	
	for(int i = 0; i < n; i++)
	{
		path[i] = a[s][i];
	}
	
	for(int i = 1; i < n; i++)
	{
		min = INF;
		for(int j = 0; j < n; j++)
		{
			if( path[j] < min && !vis[j])
			{
				pos = j;
				min = path[j];
			}
		}
		
		vis[pos] = 1;
		
		for(int j = 0;j < n;j++)
		{
			if(path[pos] + a[pos][j] < path[j] && !vis[j])
			{
				path[j] = path[pos] + a[pos][j];
			}
		}
	}
}

int main()
{
	int m;
	while(scanf("%d",&n)!=EOF)
	{
		for(int i=0;i<n;i++)
		{
			for(int j=0;j<n;j++)
			{
				a[i][j] = INF;
			}
			
			a[i][i] = 0;
		}
		
		for(int i = 0;i<n;i++)
		{
			int x,y,k,l;
			scanf("%d%d",&x,&k);
			
			for(int j=0;j<k;j++)
			{
				scanf("%d%d",&y,&l);
				
				if(a[x][y] > l)
				{
					a[x][y] = l;
				//	a[y][x] = l;
				}
			}
		}
			
			
			
		Dijkstra(0);
		
		for(int i=0;i<n;i++)
		{
			printf("%d %d\n",i,path[i]);
		}
				
	}

}

C++: #include<iostream>
#include<vector>
#include<algorithm>
#define MAX_V 100
#define INF 1e9
using namespace std;
int cost[MAX_V][MAX_V];
int d[MAX_V];
bool used[MAX_V];
int V;//頂点数

void dijkstra(int s)
{
	for (int i = 0; i < MAX_V; i++)
	{
		d[i] = INF;
		used[i] = false;
	}
	d[s] = 0;

	while (true)
	{
		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()
{
	for (int i = 0; i < MAX_V; i++)
	{
		for (int j = 0; j < MAX_V; j++)
		{
			cost[i][j] = INF;
		}
	}
	cin >> V;
	for (int i = 0; i < V; i++)
	{
		int u;//頂点番号
		cin >> u;
		int k;//出次数
		cin >> k;
		for (int j = 0; j < k; j++)
		{
			int v;
			cin >> v;
			int c;
			cin >> c;
			cost[u][v] = c;
	    }

	}

	dijkstra(0);

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

C++: #include <iostream>
#include <vector>
#include <queue>
const int inf=1e9;
using namespace std;
int main(){

  int n,now=0;
  priority_queue < pair<int,int>, vector<pair<int,int> >, greater<pair<int,int> > > g[100000];
  cin>>n;
  for(int i=0,u,k,v,c;i<n&&cin>>u>>k;i++) for(int j=0;j<k&&cin>>v>>c;j++) g[u].push(make_pair(c,v));
  int flag[100]={},c[100]={};
  for(int i=1;i<n;i++) c[i]=inf;
  for(int i=0;i<n;i++){
    int next=g[now].top().second,cnt=0;
    for(;!g[now].empty();g[now].pop()) if(!flag[g[now].top().second]){
        c[g[now].top().second]=min(c[g[now].top().second],c[now]+g[now].top().first);
        if(!cnt) next=g[now].top().second;
        cnt++;
      }
    flag[now]=1;
    now=next;
  }
  for(int i=0;i<n;i++) cout<<i<<" "<<c[i]<<endl;
  return 0;

}

C++: #include<bits/stdc++.h>
using namespace std;
#define int long long
int e[111][111],d[111];
int used[111];
signed main(){
  int n;
  cin>>n;
  int INF=1LL<<55LL;
  for(int i=0;i<n;i++)
    for(int j=0;j<n;j++)
      e[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;
      e[u][v]=min(e[u][v],c);
    }
  }
  memset(used,0,sizeof(used));
  for(int i=0;i<n;i++) d[i]=INF;
  d[0]=0;
  while(1){
    int u=-1;
    for(int i=0;i<n;i++){
      if(used[i]) continue;
      if(d[i]==INF) continue;
      if(u<0||d[i]<d[u]) u=i;
    }
    if(u<0) break;
    used[u]=1;
    for(int i=0;i<n;i++){
      d[i]=min(d[i],d[u]+e[u][i]);
    }
  }
  for(int i=0;i<n;i++) cout<<i<<" "<<d[i]<<endl;
  return 0;
}