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;
const int MAXn=100;
const int INFTY=1<<21;

int n,M[MAXn][MAXn],col[MAXn],d[MAXn],p[MAXn];

void dijkstra(int s)
{
	for(int i=0;i<n;i++)
	{
		col[i]=0;
		d[i]=INFTY;
	}
	d[s]=0;
	p[s]=-1;
	
	while(1)
	{
		int mincost=INFTY;
		int u;
		for(int i=0;i<n;i++)
		{
			if(col[i]!=2&&d[i]<mincost)
			{
				mincost=d[i];
				u=i;
			}
		}
		if(mincost==INFTY)break;
		col[u]=2;
		for(int v=0;v<n;v++)
		{
			if(col[v]!=2&&M[u][v]!=INFTY)
			{
				if(d[u]+M[u][v]<d[v])
				{
					d[v]=d[u]+M[u][v];
					p[v]=u;
					col[v]=1;
				}
			}
		}
	}
	
	for(int i=0;i<n;i++)cout<<i<<" "<<(d[i]==INFTY?-1:d[i])<<endl;
	
	return;
}

int main() {
	cin>>n;
	int id,k,v,c;
	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>>id>>k;
		for(int j=0;j<k;j++)
		{
			cin>>v>>c;
			M[id][v]=c;
		}
	}
	dijkstra(0);
	return 0;
}

C++: #include<bits/stdc++.h>
#define INF 999999999
using namespace std;

int G[110][110] = {};
int mini[110];
int used[110];

void dijkstra(int n)
{
    //init
    for(int i = 0;i < n;i++){
        mini[i] = INF;
        used[i] = 0;
    }
    mini[0] = 0;

    while(true)
    {
        int v = -1;
        for(int i = 0;i < n;i++){
            if(!used[i] && (v == -1 || mini[i] < mini[v])) v = i;
        }
        if(v == -1) break;
        used[v] = 1;

        for(int i = 0;i < n;i++){
            mini[i] = min(mini[i], mini[v]+G[v][i]);
        }
    }
}

int main()
{
    int n;
    int u, k, v, c;

    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++){
        cin >> u >> k;
        for(int j = 0;j < k;j++){
            cin >> v >> c;
            G[u][v] = c; //uiとviをつなぐコストがci
        }
    }
    dijkstra(n);
    
    for(int i = 0;i < n;i++) printf("%d %d\n", i, mini[i]);
    
    return 0;
}

C++: #include <iostream>

using namespace std;

static const int N = 100;
static const int INF = 1000000;

struct Vertex {
    bool in_S;
    int min_cost;
    int parent;
};

class SSSP {
private:
    int matrix[N][N];
    Vertex vertex[N];
    int n;

public:
    SSSP()
    {
        cin >> n;

        for (int i = 0; i < n; i++)
            for (int j = 0; j < n; j++)
                matrix[i][j] = INF;

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

    void dijkstra(int start)
    {
        for (int i = 0; i < n; i++)
        {
            vertex[i].in_S = false;
            vertex[i].min_cost = INF;
        }
        vertex[start].min_cost = 0;
        vertex[start].parent = -1;

        while (true)
        {
            int u = -1;
            int mincost = INF;
            for (int i = 0; i < n; i++)
            {
                if (!vertex[i].in_S && vertex[i].min_cost < mincost)
                {
                    mincost = vertex[i].min_cost;
                    u = i;
                }
            }

            if (mincost == INF)
                break;

            vertex[u].in_S = true;

            for (int v = 0; v < n; v++)
            {
                if (!vertex[v].in_S && matrix[u][v] != INF)
                {
                    if (vertex[u].min_cost + matrix[u][v] < vertex[v].min_cost)
                    {
                        vertex[v].min_cost = vertex[u].min_cost + matrix[u][v];
                        vertex[v].parent = u;
                    }
                }
            }
        }
    }

    void print()
    {
        for(int i = 0; i < n; i++)
            cout << i << " " << vertex[i].min_cost << endl;
    }
};

int main()
{
    SSSP mst;
    mst.dijkstra(0);
    mst.print();
}

C++: // https://onlinejudge.u-aizu.ac.jp/courses/lesson/1/ALDS1/all/ALDS1_12_B
#include <bits/stdc++.h>
using ll = long long;
using namespace std;

#define INFint 2e9+1

ll gcd(ll a, ll b) { return __gcd(a,b); }
ll lcm(ll a, ll b) { return a/gcd(a,b)*b; }

int main(){
// start
  struct edge {int to,cost;};
  int N;
  cin>>N;
  vector<vector<edge>> G(N,vector<edge>());
  for(int i(0);i<N;i++){
    int k,u;
    cin>>k>>u;
    for(int j(0);j<u;j++){
      int v,c;
      cin>>v>>c;
      G[k].push_back({v,c});
    }
  }
  vector<int> d(N);
  fill(d.begin(),d.end(),INFint);
  // first: cont, second: node number 
  priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> q;
  int start = 0;
  d[start] = 0;
  q.push({0,start});

  while(!q.empty()){
    pair<int,int> p = q.top();q.pop();                                                  
    int v = p.second;
    //if (d[v] < p.first) continue;
    for (int i(0);i<int(G[v].size());i++){
      edge e = G[v][i];
      if (d[e.to] > d[v] + e.cost){
        d[e.to] = d[v] + e.cost;
        q.push({d[e.to],e.to});
      }
    }
  }
// end
  for(int i(0);i<N;i++){
    cout << i <<" " << d[i] << endl;
  }
  return 0;
}