Go: package main

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

const BIG_COST = 200000

type Path struct {
	node int
	cost int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	nNodes := scanInt(sc)

	// 各頂点につながる頂点一覧を得るための隣接リスト
	graph := make([][]Path, nNodes)

	for i := 0; i < nNodes; i++ {
		u := scanInt(sc)
		k := scanInt(sc)
		graph[i] = make([]Path, k)
		for d := 0; d < k; d++ {
			graph[u][d] = Path{
				node: scanInt(sc),
				cost: scanInt(sc),
			}
		}
	}

	// 0 から各頂点への最小コストを保存する配列
	minCosts := make([]int, nNodes)

	minCosts[0] = 0
	for i := 1; i < nNodes; i++ {
		minCosts[i] = BIG_COST
	}

	// 各頂点が調査済みかどうかを保持する配列
	checked := make([]bool, nNodes)

	// 最小コストのパスを高速に取得するためのヒープ。
	// コストが小さいものほどルートに来るようにする。
	heap := NewHeap(func(a, b Path) bool {
		return a.cost < b.cost
	})

	heap.insert(Path{node: 0, cost: 0})
	for heap.size > 0 {
		u := heap.extractMax()

		// 隣接行列を使っていた時とは違い、ヒープには
		// 同じノードへのパスが複数含まれうる。そのため既によりコストの低い
		// パスが見つかっている場合は無視する。
		if minCosts[u.node] < u.cost {
			continue
		}

		checked[u.node] = true

		for _, v := range graph[u.node] {
			cost := v.cost + u.cost
			if !checked[v.node] && cost < minCosts[v.node] {
				minCosts[v.node] = cost
				heap.insert(Path{node: v.node, cost: cost})
			}
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i, cost := range minCosts {
		fmt.Fprintf(w, "%d %d\n", i, cost)
	}
	w.Flush()
}

func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

// --- From ALDS1_9_C: Priority Queue

type Heap struct {
	size   int
	heap   []Path
	isHigh func(a, b Path) bool
}

func NewHeap(isHigh func(a, b Path) bool) Heap {
	heap := make([]Path, 1) // 先頭は不使用
	return Heap{size: 0, heap: heap, isHigh: isHigh}
}

func (h *Heap) insert(v Path) {
	h.size += 1
	if h.size > len(h.heap)-1 {
		h.heap = append(h.heap, v)
	} else {
		h.heap[h.size] = v
	}

	for i := h.size; i > 1; {
		parent := i / 2
		if h.isHigh(h.heap[parent], h.heap[i]) {
			break
		}
		h.heap[i], h.heap[parent] = h.heap[parent], h.heap[i]
		i = parent
	}
}

func (h *Heap) extractMax() Path {
	if h.size <= 0 {
		panic("cannot extract from empty heap")
	}

	max := h.heap[1]
	h.heap[1] = h.heap[h.size]
	h.size -= 1
	h.maxHeapify(1)

	return max
}

func (h *Heap) maxHeapify(idx int) {
	left := idx * 2
	right := left + 1
	largest := idx

	if left <= h.size {
		if h.isHigh(h.heap[left], h.heap[idx]) {
			largest = left
		}
		if right <= h.size && h.isHigh(h.heap[right], h.heap[largest]) {
			largest = right
		}
	}

	if largest != idx {
		h.heap[idx], h.heap[largest] = h.heap[largest], h.heap[idx]
		h.maxHeapify(largest)
	}
}

C++: #include<iostream>
#include<vector>
#include<queue>
using namespace std;
struct Edge {
    int d, i, j;
    Edge(int d_, int i_, int j_) : d(d_), i(i_), j(j_) {}
    bool operator< (const Edge& right) const{
        return d > right.d;
    }
};
void calc(int t, vector<vector<pair<int, int > > >& G, vector<int>& distance){
    int new_black = t;
    priority_queue<Edge> temp;
    for (int i = 1; i < G.size(); i++) {
        for (int j = 0; j < G[new_black].size(); j++) {
            if (distance[G[new_black][j].first] != -1) continue;
            int dis = G[new_black][j].second + distance[new_black];
            temp.push(Edge(dis, new_black, G[new_black][j].first));
        }
        while (distance[temp.top().j] != -1) temp.pop();
        distance[temp.top().j] = temp.top().d;
        new_black = temp.top().j;
        temp.pop();
    }
}

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

    vector<int> distance(n, -1);
    distance[0] = 0;
    calc(0, G, distance);
    for (int i = 0; i < n; i++) {
        cout << i << " " << distance[i] << endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, a, b) for(int i = a; i < b; i++)
#define Rep(i, a, b) for(int i = a; i <= b; i++)
#define repr(i, a, b) for(int i = a; i >= b; i--)
#define _GLIBCXX_DEBUG
#define Vl vector<ll>
#define Vs vector<string>
#define Vp vector<pair<ll, ll>>
#define ld long double
using ll = long long;
#define ALL(v) (v).begin(),(v).end()
#define endl "\n"
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define co(x) cout << x << endl
#define coel cout << endl
#define pb push_back
#define sz(v) ((ll)(v).size())
using namespace std;  
const double pi = acos(-1.0);
const ll MOD = 1e9 + 7;
const ll INF = 1LL << 60;
#define pp pair<ll, pair<ll, ll>> 
#define fi first
#define se second

void print(Vl vec){
    rep(i, 0, sz(vec)){
        if(i) cout << " ";
        cout << vec[i];
    }
    coel;
}

////////////////////////////////////////////////////////

// デバッグを消し忘れるな！！！

// dijkstra
// 有向グラフ

const ll mx = 10005;

vector<pair<ll, ll>> adj[mx];
ll d[mx];
ll color[mx];
ll n;

// 頂点0から各頂点vまでの最短経路

void dijkstra(){
    priority_queue<pair<ll, ll>, vector<pair<ll, ll>>, greater<pair<ll, ll>>> pq;
    rep(i, 0, mx) d[i] = INF;
    d[0] = 0;
    color[0] = 1;
    pq.push({0, 0});

    while(!pq.empty()){
        pair<ll, ll> f = pq.top(); pq.pop();
        ll u = f.second; // 番号
        color[u] = 1;
        if(d[u] < f.first) continue;
        rep(j, 0, sz(adj[u])){
            ll v = adj[u][j].first;
            if(color[v])  continue;
            if(d[v] > d[u] + adj[u][j].second){
                d[v] = d[u] + adj[u][j].second;
                pq.push({d[v], v});
            }
        }
    }

    rep(i, 0, n){
        cout << i << " " << (d[i] == INF ? -1 : d[i]) << endl;
    }

}

int main() {
    cin >> n;
    rep(i, 0, n){
        ll u, k; cin >> u >> k;
        rep(j, 0, k){
            ll v, c; cin >> v >> c;
            adj[u].push_back({v, c});
        }
    }

    dijkstra();

    return 0;
}

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

#define MAX 10001
#define INF 5000001

int a[MAX][MAX];
int n;
int d[MAX];

void Relax(int u, int v){
  if(d[v]> d[u]+a[u][v]){
    d[v]=d[u]+a[u][v];
  
  }
}

void ISS(int s){
  int v;
  for(v=0; v<n; v++){
    d[v]=INF;
  }
  d[s]=0;
}

void Dijkstra(int s){
  int i, v1, v, minv, u; 
  int flag[MAX];
  ISS(s);
  
  for(i=0; i<n; i++) flag[i]=0;

  for(v1=0; v1<n; v1++){
    
      minv = INF;
      // decide u
      for ( i = 0; i < n; i++ ){
          if(flag[i]==1) continue; 
          if(d[i]<=minv){
              u=i;
              minv=d[i];
          }
      }   
      for(v=0; v<n; v++){
          if(a[u][v]==-1) continue;
          if(flag[v]==1) continue;
          /* if(a[u][v]<d[v]){
             d[v]=a[u][v];
             }*/
          Relax(u, v);
      }
      flag[u]=1;
  }
}

int main(){

  int i, j ,u ,k,v,c;
  // int a[MAX][MAX];
  cin>>n;

  for(i=0; i<n; i++){
    for(j=0; j<n; j++){
      a[i][j]=-1;
    }
  }

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

  /*for(i=0; i<n; i++){
    for(j=0; j<n; j++){
    cout<<a[i][j]<<endl;
    }
    cout<<endl;
    }*/
  Dijkstra(0);
  for(i=0; i<n; i++){
      cout<<i<<" "<<d[i]<<endl;
  }

  return 0;
}