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 <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> pll;
typedef vector<ld> vd;
typedef vector<ll> vll;
typedef vector<string> vstr;
typedef vector<vll> vvll;
typedef vector<vvll> vvvll;
typedef vector<pair<ll, ll>> vpll;
typedef priority_queue<ll, vector<ll>, greater<ll>> spqll;  // 小さい順に取り出し
typedef priority_queue<ll, vector<ll>, less<ll>> bpqll;     // 大きい順に取り出し

#define REP(i, n) for (ll i = 0; i < (ll)(n); i++)
#define FOR(i, a, b) for (ll i = (ll)a; i < (ll)b; i++)
#define IREP(i, v) for (auto i = (v).begin(); i != (v).end(); i++)
#define FI first
#define SE second
#define MP make_pair
#define MT make_tuple
#define PB push_back
#define TS to_string
#define NP next_permutation
#define ALL(v) (v).begin(), (v).end()
#define SZ(x) (ll) x.size()
#define SP(x) setprecision((ll)x)


ll INF = 1e9;
ll MOD = 1000000007;
ll LINF = 1e18;
ld EPS = 1e-9;
ld PI = M_PI;
vll dx = {1, 0, -1, 0, 1, -1, -1, 1};
vll dy = {0, 1, 0, -1, 1, 1, -1, -1};
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a;} //最大公約数
ll lcm(ll a, ll b) { return a / gcd(a, b) * b;}     //最小公倍数

void yes(){ cout << "Yes" << endl;}
void no(){ cout << "No" << endl;}

//-----------------------------------------
class warshall_floyd{
  private:
    ll N; // 頂点数
    vvll dis; // iからjまでの最短距離
    ll inf = 1e18;

  public:
    warshall_floyd(ll n){
      N = n;
      dis.resize(N,vll(N));

      for(ll i=0;i<N;i++){
        for(ll j=0;j<N;j++){
          dis[i][j] = ( i == j ? 0 : inf );
        }
      }
    }

    // 辺の入力
    void in_edge(ll to, ll from, ll cost){
      dis[to][from] = cost;
    }

    // d[i][j]を埋める
    vvll main(){
      for(ll k=0;k<N;k++){
        for(ll i=0;i<N;i++){
          for(ll j=0;j<N;j++){
            dis[i][j] = min(dis[i][j], dis[i][k] + dis[k][j]);
          }
        }
      }
      return dis;
    }

    // 負の経路の検出
    bool mns_loop(){
      for(ll i=0;i<N;i++){
        if(dis[i][i] < 0) return true;
      }
      return false;
    }
};
//-----------------------------------------

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);

  ll n;
  cin >> n;
  warshall_floyd W(n);
  REP(i,n){
    ll v, k;
    cin >> v >> k;
    REP(j,k){
      ll a, b;
      cin >> a >> b;
      W.in_edge(v,a,b);
    }
  }
  vvll tmp = W.main();
  REP(i,n) cout << i << " " << tmp[0][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];

int 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>
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;
}