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 <cstdio>
#include <algorithm>
#include <queue>
using namespace std;
static const int INFTY = (1 << 21);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<pair<int, int>> *adj;
int *d;

void dijkstra() {
    priority_queue<pair<int, int>> PQ;
    int d[n], color[n];

    for (int i = 0; i < n; i++) {
        d[i] = INFTY;
        color[n] = WHITE;
    }
    d[0] = 0;
    PQ.push(make_pair(0, 0));

    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[u] + adj[u][j].second < d[v]) {
                d[v] = d[u] + adj[u][j].second;
                // printf("d[%d] = %d\n", v, d[v]);
                PQ.push(make_pair(d[v] * (-1), v));
                color[v] = GRAY;
            }
        }
    }
    
    for (int i = 0; i < n; i++) {
        printf("%d %d\n", i, d[i]);
    }
}

int main() {
    scanf("%d", &n);

    adj = new vector<pair<int, int>>[n];

    for (int i = 0; i < n; i++) {
        int u, k;
        scanf("%d %d", &u, &k);
        for (int j = 0; j < k; j++) {
            int v, c;
            scanf("%d %d", &v, &c);
            adj[u].push_back(make_pair(v, c));
        }
    }

    dijkstra();

    return 0;
}

C++: #include <cstdio>
#include <vector>
#include <queue>

int main(void){

	int n, count, next_node, num_neighbors;
	std::vector< std::vector<int> > edges;
	std::vector< std::vector<int> > neighbors;
	std::vector<bool> isUsed;
	std::vector<int> distance;
	std::priority_queue< std::pair<int, int> > distance_heap;
	
	scanf("%d", &n);
	
	edges.resize(n);
	isUsed.resize(n);
	neighbors.resize(n);
	distance.resize(n);
	
	for(int i=0;i<n;i++){
		scanf("%d %d", &next_node, &num_neighbors);
		edges[next_node].resize(num_neighbors);
		neighbors[next_node].resize(num_neighbors);
		for (int j=0;j<num_neighbors;j++){
			scanf("%d %d", &neighbors[next_node][j], &edges[next_node][j]);
		}
		isUsed[next_node]=-false;
		distance[next_node]=300000;
	}
	isUsed[0] = true;
	count=0;
	distance[0] = 0;
	for(int i=0;i<neighbors[0].size();i++){
		distance[neighbors[0][i]] = edges[0][i];
		distance_heap.push(std::make_pair(distance[neighbors[0][i]]*(-1), neighbors[0][i]));
	}
	count=1;
	while(count<n-1){
		std::pair<int, int> p = distance_heap.top();
		distance_heap.pop();
		next_node = p.second;
		if (isUsed[next_node]) continue;
		isUsed[next_node] = true;
		for(int i=0; i<neighbors[next_node].size();i++){
			int neighbor = neighbors[next_node][i];
			if ((!isUsed[neighbor]) && (distance[neighbor] > distance[next_node] + edges[next_node][i])){
				distance[neighbor] = distance[next_node] + edges[next_node][i];
				distance_heap.push(std::make_pair(distance[neighbor]*(-1), neighbor));
			}
		}
		count ++;
	}
	for(int i=0;i<n;i++){
		printf("%d %d\n", i, distance[i]);
	}
	return 0;
}

C++: #include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<cmath>
#include<queue>

#define FOR(i,a,b) for(int i=(a);i<(b);++(i))
#define REP(i,n) FOR(i,0,n)

#define dump(x) cerr << #x << " = " <<(x)<<endl;
#define debug(x) cerr << #x << " = " <<(x) << "(L" << __LINE__ << ")" << __FILE__ << endl;

using namespace std;

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

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

void dijkstra(){
  priority_queue<P> 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()){
    P 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(void){
   
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
struct Point{
	int v,e;
	bool operator<(const Point b)const{
		return this->e > b.e;
	}
	Point(int a,int b):v(a),e(b){}
	Point():v(0),e(0){}
};

long long d[10000];
bool visit[10000] = {0};
vector <Point> G[10000];
priority_queue <Point> PQ;

const long long INF = 1e19;

void dj(int n){
	for(int i=0; i<n; i++) d[i] = INF;
	d[0] = 0;
	PQ.push(Point(0,0));
	Point p, q;
	while(!PQ.empty()){
		p = PQ.top(); PQ.pop();
		visit[p.v] = 1;
		if(d[p.v] < p.e) continue;
		int du = G[p.v].size();
		for(int i=0; i<du; i++){
			q = G[p.v][i];
			if(!visit[q.v] && q.e+d[p.v]<d[q.v]){
				d[q.v] = q.e + d[p.v];
				PQ.push(Point(q.v,d[q.v]));
			}
		}
	}
}
int main()
{	
	int n,u,du; cin>>n;
	for(int i=0; i<n; i++){
		scanf("%d%d",&u,&du);
		int v,e;
		while(du--){
			scanf("%d%d",&v,&e);
			G[u].push_back(Point(v,e));
		}
	}
	dj(n);
	for(int i=0;i<n;i++)
		printf("%d %d\n",i,d[i]);
	return 0;
}