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 <vector>
#include <stack>
#include <queue>
#include <bitset>
#include <utility>
#include <functional>
#include <numeric>

//TODO

template <class T>
using vec = std::vector<T>;

constexpr int nil = -1;
constexpr int inf = 1 << 30;

struct Edge
{
    int to;
    int cost;
};

vec<int> dijkstra(const vec<vec<Edge>>& edges)
{
    using namespace std;

    const int n = edges.size();
    vec<int> distances(n, inf);
    vec<bool> reached(n, false);

    distances[0] = 0;

    while (true)
    {
        int minCost {inf};
        int u {};

        for (int i = 0; i < n; ++i)
        {
            if (!reached[i] && distances[i] < minCost)
            {
                minCost = distances[i];
                u = i;
            }
        }

        if (minCost == inf)
            break;
        
        reached[u] = true;

        for (auto& e : edges[u])
        {
            distances[e.to] = min(distances[e.to], distances[u] + e.cost);
        }
    }

    return distances;
}

void solve()
{
    using namespace std;
    int n;
    cin >> n;

    //隣接リスト形式
    vec<vec<Edge>> edges(n);
    
    //入力
    for (int i = 0; i < n; ++i)
    {
        int v, k;
        cin >> v >> k;
        for (int j = 0; j < k; ++j)
        {
            int to, cost;
            cin >> to >> cost;
            edges[i].push_back({to, cost});
        }
    }

    auto d = dijkstra(edges);

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

int main()
{
    solve();
    return 0;
}

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

int x[10000][2000];
int x2[10000][2000];
int y[10000];
int z[10000];

int main() {
	memset(x, 1, sizeof(x));
	memset(y, 1, sizeof(y));
	int n, a, b, c, d, e;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> a >> b;
		for (int i = 0; i < b; i++) {
			cin >> c >> d;
			x[a][z[a]] = c;
			x2[a][z[a]] = d;
			z[a]++;
		}
	}
	y[0] = 0;
	e = min(n, 2000);
	for (int i = 0; i < e; i++) {
		for (int j = 0; j < n; j++) {
			for (int k = 0; k < z[j]; k++) {
				y[x[j][k]] = min(y[x[j][k]], y[j] + x2[j][k]);
			}
		}
	}
	for (int i = 0; i < n; i++) {
		cout << i << ' ' << y[i] << endl;
	}
	return 0;
}

C++: #include <stdio.h>
#include <cmath>
#include <algorithm>
#include <stack>
#include <queue>
#include <vector>
typedef long long int ll;

#define BIG_NUM 2000000000

using namespace std;

struct Node{

	Node(int arg_to,int arg_cost){
		to = arg_to;
		cost = arg_cost;
	}
	bool operator<(const struct Node &arg) const{
			return cost > arg.cost;
	};

	int to,cost;
};

int main(){

	int N;
	scanf("%d",&N);

	int** distance = new int*[N];

	for(int i = 0; i < N; i++){
		distance[i] = new int[N];
		for(int k = 0; k < N; k++)distance[i][k] = BIG_NUM;
	}

	int node,num,to,cost,D[N];;

	for(int loop = 0; loop < N; loop++){
		scanf("%d",&node);
		scanf("%d",&num);
		for(int i = 0; i < num; i++){
			scanf("%d %d",&to,&cost);
			distance[node][to] = cost;
		}
		D[loop] = BIG_NUM;
	}

	D[0] = 0;
	distance[0][0] = 0;

	bool visited[N];
	for(int i = 1; i < N; i++)visited[i] = false;
	visited[0] = true;

	priority_queue<Node> Q;

	for(int i = 1; i < N; i++){
		if(distance[0][i] != BIG_NUM){
			D[i] = distance[0][i];
			Q.push(Node(i,distance[0][i]));
		}
	}

	int min_index;

	while(!Q.empty()){
		if(Q.top().cost == D[Q.top().to]){
			min_index = Q.top().to;
			Q.pop();
		}else{
			Q.pop();
			continue;
		}

		for(int i = 1; i < N; i++){
			if(distance[min_index][i] != BIG_NUM && D[i] > D[min_index]+distance[min_index][i]){
				D[i] = D[min_index]+distance[min_index][i];
				Q.push(Node(i,D[i]));
			}
		}
	}

	for(int i = 0; i < N; i++)printf("%d %d\n",i,D[i]);

    return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<queue>
#include<vector>
#include<utility>
#include<limits>
using namespace std;
typedef pair<int, int> Edge;
int main()
{
	int n; cin >> n;
	vector< vector< Edge > > lists;

	for (int i = 0; i < n; i++)
	{
		vector<Edge> list;
		int u, k;
		cin >> u >> k;
		for (int j = 0; j < k; j++)
		{
			Edge edge;
			cin >> edge.second >> edge.first;
			list.push_back(edge);
		}
		lists.push_back(list);
	}

	vector<int> costs(n, -1);
	costs[0] = 0;
	priority_queue<Edge,vector<Edge>,greater<Edge> > queue;
	queue.push(Edge(0, 0));

	while (!queue.empty())
	{
		Edge edge = queue.top(); queue.pop();
		int dest = edge.second;
		int cost = edge.first;
		if (costs[dest]<cost)continue;
		for (Edge next : lists[dest])
		{
			next.first += cost;
			if (costs[next.second] > next.first||costs[next.second]==-1)
			{
				costs[next.second] = next.first;
				queue.push(next);
			}
		}
	}
	for (int i = 0; i < n; i++)
		cout << i << " " << costs[i] << endl;

	char c;
	cin >> c;

	return 0;
}