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;
static const int MAX = 10000;
int N;
vector<pair<int, int>> adj[MAX];
int color[MAX];
int d[MAX];
int INF = 1 << 30;

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

void pa() {
    for (int i = 0; i < N; i++) {
        cout << i << " ";
        for (int j = 0; j < adj[i].size(); j++) {
            cout << adj[i][j].second << " ";
        }
        cout << endl;
    }
    cout << endl;
}

void dijkstr() {
    int i,j;
    priority_queue<pair<int, int>> PQ;
    PQ.push(make_pair(0, 0));
    
    d[0] = 0;
    cout << N << endl;
    for (i = 0; i < N; i++) {
        pair<int, int> p = PQ.top(); PQ.pop();
        
        //int c = p.first;
        int id = p.second;
        
        color[id] = 1;
        for (j = 0; j < adj[id].size(); j++) {
            auto node = adj[id][j];
            int c = node.first;
            int k = node.second;
            if (color[k] != 1) {
                if (d[k] > d[id] + c) {
                    d[k] = d[id] + c;
                    PQ.push(make_pair(-c, k));
                }
            }
        }
    }
}



int main(int argc, const char * argv[]) {
    int i,j;
    cin >> N;
//    pd();

    for (i = 0; i < N; i++) {
        int u,k;
        cin >> u >> k;
        color[i] = 0;
        d[i] = INF;
        for (j = 0; j < k; j++) {
            int v, c;
            cin >> v >> c;
            adj[u].push_back(make_pair(c, v));
        }
    }
    
    //pa();
    
    dijkstr();
    
    for (i = 0; i < N; i++) {
        cout << i << " " << d[i] << endl;
    }
    
    
    return 0;
}

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

const int MAX=10005;
int state[MAX],N,D[MAX];
vector<pair<int,int>> S[MAX];
priority_queue<pair<int,int>> Q;

void dijkstra(){
    int cnt=1;
    for(int i=0;i<N;i++){
        state[i]=0;
        D[i]=100000000;
    }
    state[0]=1;
    D[0]=0;
    for(int i=0;i<S[0].size();i++){
        Q.push(make_pair(-S[0][i].second,S[0][i].first));
        D[S[0][i].first]=min(D[S[0][i].first],D[0]+S[0][i].second);
    }
    while(1){
        int a=Q.top().second;
            if(state[a]==0){
            Q.pop();
            state[a]=1;
            cnt++;
            for(int i=0;i<S[a].size();i++){
                if(state[S[a][i].first]==0){
                    Q.push(make_pair(-S[a][i].second,S[a][i].first));
                    D[S[a][i].first]=min(D[S[a][i].first],D[a]+S[a][i].second);
                }
            }
        }
        else Q.pop();
        if(cnt==N) break;
    }
    return;
}


int main(){
   
    cin>>N;
    for(int i=0;i<N;i++){
        int l,a;cin>>l>>a;
        for(int j=0;j<a;j++){
            int b,c;cin>>b>>c;
            S[i].push_back(make_pair(b,c));
        }
    }
    dijkstra();
    for(int i=0;i<N;i++){
        cout<<i<<" "<<D[i]<<endl;
    }
}

C++: #include <iostream>
#include <algorithm>
#include <queue>
using namespace std;
#define MAX 10000
#define INFTY (1<<30)
#define rep(i,n)	for(int i=0;i<n;i++)
enum{
	white,
	gray,
	black,
};

int n;
vector<pair<int,int> >	adj[MAX];

void dijkstra(){
	priority_queue<pair<int,int> >	pq;
	int color[MAX];
	int d[MAX];
	rep(i,n){
		d[i]=INFTY;
		color[i]=white;
	}
	d[0]=0;
	pq.push(make_pair(0,0));
	color[0]=gray;
	while(!pq.empty()){
		pair<int,int> f=pq.top();	pq.pop();
		int u=f.second;
		color[u]=black;
		if(d[u]<f.first*(-1))	continue;
		rep(j,(int)adj[u].size()){
			int v=adj[u][j].first;
			if(color[v]==black)	continue;
			if(d[v]>d[u]+adj[u][j].second){
				d[v]=d[u]+adj[u][j].second;
				pq.push(make_pair(d[v]*(-1),v));
				color[v]=gray;
			}
		}
	}
	rep(i,n){
		cout<<i<<" "<<(d[i]==INFTY?-1:d[i])<<endl;
	}
}

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

C++: #include <iostream>
#include <queue>
using namespace std;

const int MAX = 10000;
const int INFINITY = 2 << 21;
int n;
vector<pair<int, int> > G[MAX];
int distances[MAX];
int states[MAX];

void dijkstra() {
  int id = 0;
  distances[id] = 0;
  priority_queue<pair<int, int> > PQ;
  PQ.push(make_pair(0, 0));

  while (!PQ.empty()) {
    pair<int, int> p = PQ.top(); PQ.pop();
    id = p.second;
    states[id] = 1;

    if (distances[id] < p.first * -1) continue;

    int s = G[id].size();
    for (int i = 0; i < s; i++) {
      int k = G[id][i].first;
      int v = G[id][i].second;
      if (states[k] == 1) continue;
      if (distances[id] + v < distances[k]) {
        distances[k] = distances[id] + v;
        PQ.push(make_pair(distances[k] * -1, k));
      }
    }
  }

  for (int i = 0; i < n; i++) {
    cout << i << " " << (distances[i] == INFINITY ? -1 : distances[i]) << endl;
  }
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  cin >> n;

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

  dijkstra();

  return 0;
}