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 "bits/stdc++.h"

using namespace std;

using ll = long long;
using ld = long double;
using P = pair<int, int>;
constexpr ld EPS = 1e-12;
constexpr int INF = numeric_limits<int>::max() / 2;
constexpr int MOD = 1e9 + 7;

template <typename T>
void printv(const vector<T> &v)
{
    int sz = v.size();
    for (int i = 0; i < sz; i++)
    {
        cout << v[i] << " \n"[i == sz - 1];
    }
}

struct UnionFind
{
    vector<int> data;
    UnionFind(int size) : data(size, -1) {}
    bool unite(int x, int y)
    {
        x = root(x);
        y = root(y);
        if (x != y)
        {
            if (data[y] < data[x])
                swap(x, y);
            data[x] += data[y];
            data[y] = x;
        }
        return x != y;
    }
    bool find(int x, int y)
    {
        return root(x) == root(y);
    }
    int root(int x)
    {
        return data[x] < 0 ? x : data[x] = root(data[x]);
    }
    int size(int x)
    {
        return -data[root(x)];
    }
};

struct Edge
{
    int from, to, cost;
    Edge(int from, int to, int cost) : from(from), to(to), cost(cost) {}
};

typedef vector<Edge> Edges;
typedef vector<Edges> Graph;

bool operator<(const Edge &e, const Edge &f)
{
    return e.cost > f.cost;
}

vector<int> dijkstra(const Graph &g, int s)
{
    vector<int> d(g.size(), INF);
    d[s] = 0;
    priority_queue<P, vector<P>, greater<P>> que;
    que.push(P(0, s)); // P(dis, pos)
    while (!que.empty())
    {
        int dist = que.top().first;
        int v = que.top().second;
        que.pop();
        if (d[v] < dist)
            continue;
        for (const auto &e : g[v])
        {
            if (d[e.to] <= d[v] + e.cost)
                continue;
            d[e.to] = d[v] + e.cost;
            que.push(P(d[e.to], e.to));
        }
    }
    return d;
}
int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;
    Graph g(n);
    for (int i = 0; i < n; i++)
    {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++)
        {
            int v, c;
            cin >> v >> c;
            g[u].push_back(Edge{u, v, c});
        }
    }
    vector<int> res = dijkstra(g, 0);
    for (int i = 0; i < n; i++)
        cout << i << " " << res[i] << endl;
}

C++: #include <iostream>
#include <algorithm>
#include <queue>
 using namespace std;
 static const int WHITE = 0;
 static const int GRAY = 1;
 static const int BLACK =2;
 static const int MAX = 10000;
 static const int INFTY = (1<<20);
 
 int n;
 vector<pair<int,int> >adj[MAX];
 
 void dij(){
 	priority_queue<pair<int,int> >PQ;
 	int color[MAX];
 	int d[MAX];
 	for(int i=0;i<n;i++){
 		color[i] = WHITE;
 		d[i] = INFTY;
 	}
 	
 	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] = GRAY;
 		
 		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][v].second){
 				d[v] = d[u]+adj[u][v].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(){
 		cin>>n;
 	
 	int k,u,c,v;
 	for(int i=0;i<n;i++){
 		cin>>u>>k;
 		for(int j=0;j<k;j++){
 			cin>>c>>v;
 		adj[u].push_back(make_pair(c,v));
 		}
 	}
 	dij();
 	return 0;
 }

C++: #include <bits/stdc++.h>
using namespace std;
struct Graph{
  using seen_t=size_t; using ver_t=size_t; using edge_t=pair<ver_t,seen_t>;
  const seen_t NO=1e9;
  vector<seen_t> seen;
  vector<vector<edge_t>> edge;
  Graph(size_t n): seen(n,NO), edge(n) {}

  void search(ver_t v0){
    seen[v0]=0;
    priority_queue<pair<seen_t,ver_t>,vector<pair<seen_t,ver_t>>,greater<pair<seen_t,ver_t>>> que; que.push(make_pair(0,v0)); // dijkstra
    ver_t curv; seen_t alt;
    while(!que.empty()){
      curv=que.top().second; que.pop(); // dijkstra
      for(const auto& nextv:edge[curv]){
        alt=seen[curv]+nextv.second;
        if(seen[nextv.first]>alt && alt<NO){
          seen[nextv.first]=alt;
          que.push(make_pair(alt,nextv.first)); // dijkstra
        }
      }
    }
  }
};
ostream& operator<<(ostream& os, const Graph& x){
  for(size_t i=0; i<x.edge.size(); ++i){
    cout<<(i)<<' '<<x.seen[i]<<'\n';
  }
  return os;
}
int32_t main(){
  ios::sync_with_stdio(false); cin.tie(0);
  size_t n; cin>>n;
  Graph graph(n);
  size_t u,k,v,c;
  for(size_t i=0; i<n; ++i){
    cin>>u>>k;
    graph.edge[u].resize(k);
    for(size_t j=0; j<k; ++j){
      cin>>v>>c; graph.edge[u][j]=make_pair(v,c);
    }
  }
  graph.search(0);
  cout<<graph;
}