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>
int main(){
  int u,k,C,V,A[1000][1000],D[1000][1000],n;
  std::cin >> n;
  for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j] = 200001;
  for(int i=0;i<n;i++){ 
    std::cin >> u >> k;
    for(int j=0;j<k;j++){
      std::cin >> V >> C;
      D[u][V] = C;
    } 
  }
  for(int i=0;i<n;i++)D[i][i] = 0;
  for(int k=0;k<n;k++)for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j]= std::min(D[i][j],D[i][k] + D[k][j]);
  for(int i=0;i<n;i++)std::cout << i << " " << D[0][i] << std::endl;
  return 0;
}

C++: #include <iostream>
#include <vector>
using namespace std;
typedef unsigned short ushort;

class blanch{
	public:
		bool visited;
		int distance;
		ushort from;
		ushort to;
};
typedef vector <blanch> vb;
typedef vector <vb> vvb;

int make_graph(vvb &graph, vb &nodes){

	int n=nodes.size();
	for (ushort i=0; i<n; i++){
		nodes[i].visited = false;
		nodes[i].distance = INT_MAX;
	}

	for (ushort i=0; i<n; i++){
		int i2, n2;
		cin>>i2;
		cin>>n2;

		blanch bl0;
		bl0.visited = false;
		bl0.from = i2;

		for (ushort j=0; j<n2; j++){
			ushort j2;
			cin>>bl0.to;
			cin>>bl0.distance;

			graph[i2].push_back(bl0);
		}
	}
	return 0;
}

int Shortest_Path(vvb &graph, vb &nodes){

	int n = graph.size(), p1=0;
	nodes[p1].distance = 0;
	int p2;
	while (p1 != -1){
		nodes[p1].visited=true;
		for (int i = 0; i < (int)graph[p1].size(); i++){
			blanch tmp = graph[p1][i];
			p2=tmp.to;
			if (nodes[p2].visited==false){
				int tmp2 = tmp.distance + nodes[p1].distance;
				if (tmp2 < nodes[p2].distance){
					tmp.distance = tmp2;
					nodes[p2] = tmp;
				}
			}
		}
		p1 = -1;
		int tmp;
		tmp = INT_MAX;
		for (int i=0; i<n; i++){
			if (nodes[i].visited==false && nodes[i].distance<tmp){
				p1 = i;
				tmp = nodes[i].distance;
			}
		}
	}
	return 0;
}

int resultout(vb &nodes){
	int n = nodes.size();
	for (int i=0; i<n; i++){
		cout<<i<<" "<<nodes[i].distance<<endl;
	}
	return 0;
}

int main(void){

	int n;
	cin>>n;
	vvb G(n, vb());
	vb nodes(n);

	make_graph(G, nodes);

	Shortest_Path(G, nodes);

	resultout(nodes);
	G.clear();
	nodes.clear();

	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define ll long long
#define rep(i, n) for (ll i = 0; i < (ll)n; ++i)
ll dx[4] = { 0, 1, 0, -1 };
ll dy[4] = { 1, 0, -1, 0 };
static const int INF = 1 << 21;
static const int MOD = 1e9 + 7;
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[MAX]; // 重み付き有向グラフの隣接リスト表現

void dijkstra()
{
    priority_queue<pair<int, int>> PQ;
    int color[MAX];
    int d[MAX];
    rep(i, n)
    {
        d[i] = INF;
        color[i] = WHITE;
    }

    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;

        // 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;
        }

        rep(j, adj[u].size())
        {
            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;
                // priority_queueはデフォルトで大きい値を優先するため-1を掛ける
                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()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int k, u, v, c;
    cin >> n;

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

    dijkstra();

    return 0;
}

C++: #include<iostream>
#include<climits>
#include<cstdio>
using namespace std;

typedef struct{
  int A[10001];
  int ans;
}node;
node T[10001];
int head=0;
int tail=1;
int n;

void function(int num){
  int *Q=new int[50000];
  Q[0]=0;
  while(true){
    if(head==tail)break;
    num=Q[head++];
    if(head==49999)head=1;
    for(int i=0;i<n;i++){
      if(T[num].A[i]!=-1){
	if(T[i].ans>T[num].ans+T[num].A[i]){
	  T[i].ans=T[num].ans+T[num].A[i];
	  Q[tail++]=i;
	  if(tail==49999)tail=1;
	}
      }
    }
  }
  delete [] Q;
}

int main(){
  int num,son,z,w;
  cin>>n;
  for(int i=0;i<n;i++){
    for(int j=0;j<n;j++){
      T[i].A[j]=-1;
    }
  }


  for(int i=0;i<n;i++){
    scanf("%d%d",&num,&son);
    T[num].ans=INT_MAX;
    for(int j=0;j<son;j++){
      scanf("%d%d",&z,&w);
      T[num].A[z]=w;
      }
  }

  T[0].ans=0;
  function(0);
 
  for(int i=0;i<n;i++){
      cout<<i<<" "<<T[i].ans<<endl;
  }
  return 0;
}