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<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 << 21);

int n;
vector<pair<int, int> > adj[MAX]; //重み付き有向グラフの隣接リスト表現

void dijkstra(int s){
    priority_queue<pair<int, int> > PQ;
    int d[MAX], color[MAX];
    for(int i = 0; i < n; i++){
        d[i] = INFTY;
        color[i] = WHITE;
    }

    d[s] = 0;
    PQ.push(make_pair(0, s));
    color[s] = GRAY;

    while( !PQ.empty()){
        pair<int, int> f = PQ.top(); PQ.pop();
        int u = f.second;
        color[u] = BLACK;
/*
        //最小値を取り出し、それが最短でなければ無視
        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;
                //priority_queue　はデフォルトで大きい値を優先するため -1 をかける
                PQ.push(make_pair(d[v] * (-1), v)); //pqは一つ目の値でソートされるため、第一項に距離を持ってきている
                color[v] = GRAY;
            }
        }
    }

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

int main(){
    cin >> n;
    int u, k, v, c;

    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));
        }
    }

    dijkstra(0);

    return 0;
}

C++: #include <vector>
#include <iostream>
#include <algorithm>
#include <limits>
#include <queue>

using namespace std;
using graph = vector<vector<int>>;


struct edge {
    int src;
    int dst;
    int weight;

    edge(int src, int dst, int w) : src(src), dst(dst), weight(w) {}
};

bool operator < (const edge &a, const edge &b) {
  return a.weight > b.weight;
}


int main() {
    int n;
    cin >> n;

    graph G(n, vector<int>(n, -1));
    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][v] = c;
        }
    }

    // Dijkstra's algorithm (with pritority queue)
    vector<int> d(n, -1);
    vector<bool> visited(n, false);
    priority_queue<edge> Q;

    Q.push(edge(-1, 0, 0));
    while (!Q.empty()) {
        auto e = Q.top(); Q.pop();
        if (visited[e.dst])
            continue;
        d[e.dst] = e.weight;
        visited[e.dst] = true;

        int i = e.dst;
        int minw = numeric_limits<int>::max();
        for (int j = 0; j < n; ++j) {
            if (visited[j] || G[i][j] < 0)
                continue;
            int w = G[i][j] + d[i];
            if (w < minw) {
                minw = w;
                Q.push(edge(i, j, w));
            }
        }
    }

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

    return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;

typedef pair<int, int> P;

const int INF = 1 << 29;

int main() {
  int n;
  cin >> n;

  vector<vector<P>> edge(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;
      edge[u].push_back(P(c, v));
    }
  }

  vector<int> dist(n, INF);
  priority_queue<P, vector<P>, greater<P>> que;
  dist[0] = 0;
  que.push(P(0, 0));
  while (!que.empty()) {
    P p = que.top();
    que.pop();

    for (int i = 0; i < edge[p.second].size(); i++) {
      if (dist[edge[p.second][i].second] > p.first + edge[p.second][i].first) {
        dist[edge[p.second][i].second] = p.first + edge[p.second][i].first;
        que.push(
            P(p.first + edge[p.second][i].first, edge[p.second][i].second));
      }
    }
  }

  for (int i = 0; i < n; i++) {
    cout << i << " " << dist[i] << "\n";
  }

  return 0;
}

C++: #include<iostream>
#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 GRAY = 1;
static const int BLACK = 2;

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

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

  for(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>a = PQ.top(); PQ.pop();

    int u = a.second;
    color[u] = BLACK;

    if(d[u] < a.first*(-1)) continue;

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

int main(){
  int i, j, k, u, v, c;

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

  dijkstra();

  return 0;
}