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<cstring>
#include<string>
#include<algorithm>
#include<bitset>
#include<vector>
#include<deque>
#include<queue>
#include<map>
#include<set>
#include<stack>
#include<cmath>
#include<iomanip>
#include <functional>
using namespace std;
typedef long long ll;
const int mod = 1000000007;
const int INF = 1 << 28;
//cout << fixed << std::setprecision(9)
//memset(a, 0, sizeof(a));
//--------------------------

const int MAX = 10000;
const int WHITE = 0;
const int GRAY = 1;
const int BLACK = 2;
int n, M[MAX][MAX];

int dijkstra()
{
	int minv;
	int d[MAX];
	int color[MAX];

	for (int i = 0; i < n; i++) {
		d[i] = INF;
		color[i] = WHITE;
	}

	d[0] = 0;
	color[0] = GRAY;

	while (1) {
		minv = INF;
		int u = -1;
		for (int i = 0; i < n; i++) {
			if (minv > d[i] && color[i] != BLACK) {
				u = i;
				minv = d[i];
			}
		}

		if (u == -1) break;
		color[u] = BLACK;
		for (int v = 0; v < n; v++) {
			if (M[u][v] != INF && color[v] != BLACK) {
				if (d[v] > d[u] + M[u][v]) {
					d[v] = d[u] + M[u][v];
					color[v] = GRAY;
				}
			}
		}
	}

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

	return 0;
}

int main()
{
	cin >> n;
	for (int i = 0; i < n; i++)
		for (int j = 0; j < n; j++)
			M[i][j] = INF;

	int k, c, u, v;
	for (int i = 0; i < n; i++) {
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			cin >> v >> c;
			M[u][v] = c;
		}
	}

	dijkstra();

	return 0;
}

C++: #include<iostream>
#include<iomanip>
#include<algorithm>
#include<bitset>
#include<cctype>
#include<cmath>
#include<cstdio>
#include<cstring>
#include<functional>
#include<limits>
#include<list>
#include<map>
#include<set>
#include<stack>
#include<string>
#include<sstream>
#include<queue>
#include<vector>
using namespace std;

#define MOD 1000000007
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3fLL

#define MAX 10000
#define WHITE 0
#define GRAY 1
#define BLACK 2

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

typedef pair<int, int> pii;

void dijkstra() {
	priority_queue<pii, vector<pii>, greater<pii> >PQ; //d[id] d
	int color[MAX] = {},
		d[MAX];
	fill(d, d + MAX, INF);
	d[0] = 0;

	//?§????????????\
	PQ.push(make_pair(0, 0));
	color[0] = GRAY;

	//PQ???????´????????????°
	while (!PQ.empty()) {
		//d????????§???(-????°????)??¨??????????´????????????????
		pii f = PQ.top(); PQ.pop();

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

		//????????§???????????°??????
		if (d[u] < f.first) { 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;
				PQ.push(make_pair(d[v], v));
				color[v] = GRAY;
			}
		}
	}
	for (int i = 0; i < n; i++) {
		cout << i << " " << (d[i] == INF ? -1 : d[i]) << endl;
	}
}

int main() {
	cin >> 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<bits/stdc++.h>
using namespace std;

short cost[10000][10000];//cost[a][b] a??????b????§?????????????????????????
long long int d[10000];//??????s?????????????°??????¢
bool used[10000];
int arrow;//????????°

const int INF = 10000000;

void dijkstra(){
  fill(d,d+arrow,INF);
  fill(used,used + arrow,false);
  d[0] = 0;

  while(1){
    int v=-1;
    // ???????????????????????????????????????????????¢???????°???????????????¢???
    for(int u=0;u<arrow;u++){
      if(!used[u] && (v == -1 || d[u] < d[v])) v = u;
    }

    if(v == -1) break;

    used[v] = true;

    for(int u=0; u<arrow; u++){
      if(cost[v][u] != INF){
        d[u] = min(d[u],d[v] + cost[v][u]);
      }
    }
  }

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

}

int main(){

    cin >> arrow;

    int n,a,v,c;



    for(int i=0;i<arrow;i++){
      for(int j=0;j<arrow;j++){
        cost[i][j] = INF;
      }
    }

    for(int u=0;u<arrow;u++){

      cin >> n >> a;

      for(int i=0; i<a;i++){
        cin >> v >> c;
        cost[n][v] = c;
      }
    }

    dijkstra();

    return 0;
}