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++: #define _GLIBCXX_DEBUG
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define ALL(v) v.begin(), v.end()
typedef long long ll;

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

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

#define AMAX 10010
#define INF 1001001001

int d[AMAX],color[AMAX];
vector<pair<int,int>> M[AMAX];
int n;

void dijk(int s){
  
  rep(i,n){
    d[i]=INF;
    color[i]=0;
  }
  d[s]=0;
  
  priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> p;
  p.push({0,s});
  
  pair<int,int> u;
  while(!p.empty()){
    u=p.top(); p.pop();
    color[u.second]=2;
    
    for(auto v:M[u.second]){
      if(color[v.first]!=2){
        if(d[u.second]+v.second<d[v.first]){
          d[v.first]=d[u.second]+v.second;
          color[v.first]=1;
          p.push({d[v.first],v.first});
        }
      }
    }
  }

}

int main(){
  cin>>n;
  
  int u,k,v,c;
  rep(i,n){
    cin>>u>>k;
    rep(j,k){
      cin>>v>>c;
      M[u].push_back({v,c});
    }
  }
  
  dijk(0);
  
  rep(i,n) cout<<i<<" "<<d[i]<<endl;
      
  return 0;
}

C++: #include <iostream>
#include <limits.h>
#include <vector>
#include <queue>

using namespace std;

struct Node {
    int id;
    int cost;
    bool done;
    vector<int> next_node;
    vector<int> len_cost;

    bool operator<(const Node& right) const {
        return cost > right.cost;
    }
} node[100];

int main() {
    int n, id, k;

    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> id >> k;
        node[id].id = id;
        node[id].cost = INT_MAX;
        node[id].done = false;
        node[id].next_node.resize(k);
        node[id].len_cost.resize(k);
        for (int j = 0; j < k; j++) {
            cin >> node[id].next_node[j] >> node[id].len_cost[j];
        }
    }

    priority_queue<Node> q;
    node[0].cost = 0;
    q.push(node[0]);
    while (!q.empty()) {
        Node temp = q.top();
        q.pop();

        if (temp.done == true) {
            continue;
        }
        node[temp.id].done = true;

        for (int i = 0; i < temp.next_node.size(); i++) {
            int to = temp.next_node[i];
            int cost = temp.cost + temp.len_cost[i];
            if (node[to].cost > cost) {
                node[to].cost = cost;
                if (node[to].done == false) {
                    q.push(node[to]);
                }
            }
        }
    }

    for (int i = 0; i < n; i++) {
        cout << i << " " << node[i].cost << endl;
    }
    
    return 0;
}

C++: #include <iostream>
#include <vector>
#include<algorithm>
#include <string>
#include <set>
#include <limits.h>
#include <map>
#include <queue>
#include <stack>

using namespace std;

#define rip(i,n,s) for (int i=(s);i<(int)(n);i++)
#define all(a) (a).begin(),(a).end()
typedef long long ll;
typedef pair<long long, int> P;

void dijk(vector<vector<P> > &da, int s, vector<ll> &ans) {
	priority_queue<P,vector<P>,greater<P> > q;
	int x = da[s].size();
	rip(i, x, 0) {
		q.push(da[s][i]);
	}
	ans[s] = 0;
	while (!q.empty()) {
		P no = q.top();
		q.pop();
		//printf("%lld %d\n", no.first, no.second);
		if (ans[no.second] < 0) {
			x = no.second;
			ans[x] = no.first;
			int size = da[x].size();
			rip(i, size, 0) {
				P PA = make_pair(da[x][i].first + no.first, da[x][i].second);
				q.push(PA);
			}
		}
	}
}

int main() {
    int n;
    cin >> n;
    vector<vector<P> >  da(n,vector<P>(0));
    rip(i,n,0){
        int x;
        cin >> x;
        cin >> x;
        int v,c;
        rip(j,x,0){
            cin >> v >> c;
            da[i].push_back(make_pair(c,v));
        }
    }
    vector<ll> ans(n,-1);
    dijk(da,0,ans);
    rip(i,n,0){
        printf("%d %lld\n",i,ans[i]);
    }
}

C++: #include<iostream>
#include<stdio.h>
#include<algorithm>
#include<queue>

using namespace std;

static const int MAX=10000;
static const int INFTY=(1<<20);
static const int WHITE=0;
static const int BLACK=2;
static const int GRAY=1;

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

void diks(){
    priority_queue<pair<int, int> >PQ;
    int color[MAX];
    int d[MAX];
    for(int i = 0; i < n; i++){
        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;   
        }
        for(int j = 0; j < adj[u].size(); j++){
            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;
            }
        }
    }
    for(int i = 0; i < n; i++){
        cout<<i<<" "<<(d[i]==INFTY?-1:d[i])<<endl;
    }
}

int main(){
    int k,u,v,c;
    cin >> n;
    for(int i = 0; i < n; i++){
        cin >> u >> k;
        for(int j = 0; j < k; j++){
            cin >> v >> c;
            adj[u].push_back(make_pair(v,c));
        }
    }
    diks();
    return 0;
}