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<cstdio>
#include<cstdlib>
#include<string.h>
#include<stack>
#include<queue>
#include<vector>
using namespace std;

int n;
int d[10000], p[10000];
int c[10000];
priority_queue<pair<int, int> > q;
vector<pair<int, int> > v[10000];


void prim(){
  d[0] = 0;
  p[0] = -1;

  q.push(make_pair(0, 0));

  while(q.empty() == 0){
    int u;
    pair<int, int> f = q.top();
    q.pop();
    u = f.second;

    c[u] = 2;

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

    for(int i = 0; i < v[u].size(); i++){
      int a = v[u][i].first;
      if(c[a] != 2){
        if(v[u][i].second + d[u] < d[a]){
          d[a] = v[u][i].second + d[u];
          p[a] = u;
          c[a] = 1;
          q.push(make_pair(d[a] * (-1), a));
        }

      }
    }
  }
}

int main(){

  cin >> n;

  for(int i = 0; i < n; i++){
    c[i] = 0;
    d[i] = 1000000;
    int id, k, x;
    cin >> id >> k;

    for(int j = 0; j < k; j++){
      int x, y;
      cin >> x >> y;
      v[id].push_back(make_pair(x, y));
    }
  }

  prim();

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

  return 0;
}

C++: #include <iostream>
#include <queue>
#include <utility>
#include <vector>

#define MAX_NODE 10000
#define INF 1000000000

using namespace std;

struct Edge {
	int to, w;
};
typedef pair<int, int> P;

vector<Edge> adj[MAX_NODE];
int d[MAX_NODE];

void dijkstra(int n, int start) {
	priority_queue<P, vector<P>, greater<P>> que;
	fill(d, d + n, INF);

	d[start] = 0;
	que.push({0, start});
	while (!que.empty()) {
		P p = que.top();
		que.pop();
		int from = p.second;

		if (d[from] < p.first)
			continue;

		for (auto& e : adj[from])
			if (d[from] + e.w < d[e.to]) {
				d[e.to] = d[from] + e.w;
				que.push({d[e.to], e.to});
			}
	}
}

int main() {
	int n;

	cin >> n;

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

	dijkstra(n, 0);

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

	return 0;
}

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

using namespace std;

vector<pair<int, int>> adja[10000];

#define INF (1 << 30)

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

	cin >> n;
	for (int i = 0; i < n; ++i) {
		cin >> id >> k;
		for (int j = 0; j < k; ++j) {
			cin >> a >> b;
			adja[id].push_back(make_pair(a, b));
		}
	}

	priority_queue<pair<int, int>> que;
	que.push(make_pair(0, 0)); //cost, node
	int cost[10000];
	fill(cost, cost + n, INF);
	cost[0] = 0;

	while (!que.empty()) {
		pair<int, int> top = que.top();
		que.pop();

		for (int j = 0, len = adja[top.second].size(); j < len; ++j) {
			if (cost[adja[top.second][j].first] > top.first + adja[top.second][j].second) {
				cost[adja[top.second][j].first] = top.first + adja[top.second][j].second;
				que.push(make_pair(top.first + adja[top.second][j].second, adja[top.second][j].first));
			}
		}
	}

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

	return 0;
}

C++: #include <algorithm>
#include <iostream>
#include <queue>
using namespace std;

static const int Max = 100;
static const int Inf = 1000000;
enum State {
	Not_Searched = 0,
	Connected = 1,
	Searched = 2
};

int n = 0;
vector<pair<int, int> > adj[Max]; // pair<??£??\??????index, ??????cost> 

void dijkstra() {
	priority_queue<pair<int, int> > pq; // pair<start ???????????????????????????????????§????????????????´???????idx>
	int st[Max];
	int min_cost[Max];
	for (int i = 0; i < n; i++) {
		st[i] = Not_Searched;
		min_cost[i] = Inf;
	}

	min_cost[0] = 0;
	pq.push(make_pair(0, 0));
	st[0] = Connected;

	while (!pq.empty()) {
		pair<int, int> f = pq.top();
		pq.pop();
		int u = f.second;
		st[u] = Searched;

		if (min_cost[u] < f.first * (-1)) continue;

		for (int i = 0; i < adj[u].size(); i++) {
			int adj_u_idx = adj[u][i].first;
			if (st[adj_u_idx] == Searched) continue;
			if (min_cost[adj_u_idx] > min_cost[u] + adj[u][i].second) {
				min_cost[adj_u_idx] = min_cost[u] + adj[u][i].second;
				pq.push(make_pair(min_cost[adj_u_idx]*(-1), adj_u_idx));
				st[adj_u_idx] = Connected;
			}
		}
	}
	for (int i = 0; i < n; i++) {
		cout << i << " " << (min_cost[i] == Inf ? -1 : min_cost[i]) << endl;
	}
	return;
}

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

	dijkstra();
	return 0;
}