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 weight = int;

struct edge {
    int to;
    weight cost;
};

using edges = std::vector<edge>;
using graph = std::vector<edges>;

// when g has neg cycle, second -> false
std::pair<std::vector<weight>, bool> spfa(graph const& g, int s) {
    constexpr weight inf = std::numeric_limits<weight>::max() / 2;
    const int n = g.size();
    std::vector<weight> d(n, inf);
    std::vector<int> in_q(n), count(n);
    std::queue<int> que;
    d[s] = 0;
    que.emplace(s);
    in_q[s] = true;
    ++count[s];
    bool neg_cycle = false;
    [&]() {
        while(!que.empty()) {
            int v = que.front();
            que.pop();
            in_q[v] = false;
            for(auto& e : g[v]) {
                if(d[v] != inf && d[e.to] > d[v] + e.cost) {
                    d[e.to] = d[v] + e.cost;
                    if(!in_q[e.to]) {
                        que.emplace(e.to);
                        in_q[e.to] = true;
                        ++count[e.to];
                        if(count[e.to] >= n) {
                            neg_cycle = true;
                            return;
                        }
                    }
                }
            }
        }
    }();

    return std::make_pair(d, !neg_cycle);
}

using namespace std;

int main() {
    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{v, c});
        }
    }

    auto ans = spfa(g, 0).first;
    for(int i = 0; i < n; ++i) {
        cout << i << ' ' << ans[i] << endl;
    }
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <queue>
using namespace std;
const int maxx=10010;
const int infinity=1<<30;

int main() {
	int n,a,b,c,e;
	vector<pair<int, int> > A[maxx];
	bool flag[maxx];
	int d[maxx];
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>a>>b;
		for(int j=0;j<b;j++){
			cin>>c>>e;
			A[a].push_back(make_pair(c,e));
		}
	}
	for(int i=0;i<n;i++){
		flag[i]=false;
		d[i]=infinity;
	}
	priority_queue<pair<int,int> > PQ;
	d[0]=0;
	PQ.push(make_pair(0, 0));
	while(PQ.empty()==0){
		pair<int, int> u=PQ.top();
		PQ.pop();
		//cout<<u.first<<" "<<d[u.first]<<endl;
		flag[u.second]=true;
		int len=A[u.second].size();
		for(int i=0;i<len;i++){
			int v=A[u.second][i].first;
			if(flag[v]==false && d[u.second]+A[u.second][i].second<d[v]){
				d[v]=d[u.second]+A[u.second][i].second;
				PQ.push(make_pair(d[v]*(-1),v));
			}
		}
	}

	for(int i=0;i<n;i++) cout<<i<<" "<<(d[i]==infinity ? -1 : d[i])<<endl;

	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n) ; i++)
constexpr auto INF = 2147483647;
typedef long long ll;

static const int MAX = 10000;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

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

void dijkstra(){
  priority_queue<pair<int,int>> pq;
  int color[MAX], d[MAX];
  rep(i,n){
    color[i] = WHITE;
    d[i] = INF;
  }
  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_vec[u].size(); j++){
      int v = Adj_vec[u][j].first;
      if(color[v] == BLACK) continue;
      if(d[v] > d[u] + Adj_vec[u][j].second){
        d[v] = d[u] + Adj_vec[u][j].second;
        pq.push(make_pair(d[v] * -1, v));
        color[v] = GRAY;
      }
    }
  }
  rep(i,n){
    cout << i << " " << (d[i] == INF ? -1 : d[i]) << endl;
  }
}

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

  dijkstra();

  return 0;
}

C++: #include <iostream>
#include <vector> 
#include <algorithm>
#include <queue>
#include <cstdio> 
using namespace std;
static const int MAX = 10000;
static const int INFTY = (1<<21);
int d[MAX],color[MAX];
int n;
vector<pair<int, int> > adj[MAX];

void dijkstra()
{
    priority_queue<pair<int, int> > PQ;
    for (int i = 0; i < n; i++)
    {
        d[i] =INFTY;
        color[i] = 0;
    } 
    d[0] = 0;
    PQ.push(make_pair(0,0));
    color[0] = 1;
    while (!PQ.empty())
    { 
        pair<int, int> f = PQ.top(); PQ.pop();
        int u = f.second;
        color[u] = 2;
        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] == 2) 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] = 1;
            } 
        } 
    } 

    return;
}


int main()
{
    //freopen("in3.txt","r",stdin);
    int u,k,v,c;
    cin>>n;
    for (int i = 0; i < n; i++)
    {
        cin>>u>>k;
        for (int j = 0; j < n; j++)
        {
            cin>>v>>c;
            adj[u].push_back(make_pair(v,c));
        } 
    } 
    dijkstra();
    for (int i = 0; i < n; i++)
    {
        cout<<i<<" "<<d[i]<<endl; 
    } 
    return 0;
}