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 <algorithm>
#include <queue>
using namespace std;

int n;
vector <pair<int, int> > adj[10000];

//dijkstra
void dijkstra() {
  priority_queue<pair<int, int> > PQ;
  int d[10000];
  for ( int i = 0; i < n; i++ ) {
    d[i] = 10000000;
  }
  d[0] = 0;
  PQ.push(make_pair(0,0));

  while ( !PQ.empty() ) {
    pair<int, int> f = PQ.top(); PQ.pop();
    int u = f.second;
    if ( d[u] < f.first * -1 ) continue;

    for ( int j = 0; j < adj[u].size(); j++ ) {
      int v = adj[u][j].first;
      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));
      }
    }
  }

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

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

  return 0;
}

C++: #include <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>

#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define repi(i,a,b) for(int i = (a); i < (b); i++)

using namespace std;

typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;

const int INF=1<<29;
const double EPS=1e-9;

const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};
const int MAX_N =10000;
int V;
int cost[MAX_N][MAX_N];
int d[MAX_N];
bool visit[MAX_N];
void dijkstra(int s){
	d[s]=0;
	while(true){
		int v =-1;
		for(int u = 0;u < V;u++){
			if(!visit[u]&&(v==-1||d[u] < d[v])){
				v = u;
			}
		}
		if(v==-1)break;
		visit[v]=true;
		for(int u = 0;u < V;u++){
			d[u] =min(d[u],d[v]+cost[v][u]);
		}
	}
}

int main(){
	cin>>V;
	for(int i =0;i <V;i++){
		d[i]=INF;
		visit[i]=false;
		for(int j =0;j <V;j++){
			cost[i][j]=INF;

		}
	}
	for(int i =0;i < V;i++){
		int u,k;
		cin>>u>>k;
		for(int j =0;j <k;j++){
			int v,c;
			cin>>v>>c;
			cost[u][v]=c;
		}
	}
	dijkstra(0);
	for(int i =0;i <V;i++){
		cout <<i<<" "<<d[i]<<endl;
	}
	return 0;
}

C++: #include <algorithm>
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(x) (x).begin(), (x).end()
#define ll long long
#define ld long double
#define INF 1000000000000000000
typedef pair<ll, ll> pll;
typedef pair<int, int> pint;

struct edge {
    ll to;
    ll cost;
};

int N;
vector<vector<edge>> G;
vector<ll> d(150);

void dijkstra() {
    priority_queue<pll, vector<pll>, greater<pll>> que;
    que.push({0, 0});
    d.assign(N, INF);
    d[0] = 0;
    while (!que.empty()) {
        pll p = que.top();
        que.pop();
        int v = p.second;
        if (d[v] < p.first)
            continue;

        for (int i = 0; i < G[v].size(); i++) {
            edge e = G[v][i];
            if (d[e.to] > d[v] + e.cost) {
                d[e.to] = d[v] + e.cost;
                que.push({d[e.to], e.to});
            }
        }
    }
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    cin >> N;
    G.resize(N);
    rep(i, N) {
        ll a, b;
        cin >> a >> b;
        rep(j, b) {
            ll c, d;
            cin >> c >> d;
            G[a].push_back({c, d});
        }
    }

    dijkstra();
    rep(i, N) { cout << i << " " << d[i] << endl; }
}

C++: #include<bits/stdc++.h>
using namespace std;
#define MOD 1000000007
#define INF (1<<20)
#define white 0
#define gray 1
#define black 2

int n;
vector<pair<int,int> > W[10000]; 
int color[10000],d[10000],p[100];

void dijkstra(int s) {
  d[s] = 0;
  priority_queue<pair<int,int> > PQ;
  PQ.push(make_pair(0,s));

  while(!PQ.empty()) {
    pair<int,int> f = PQ.top();PQ.pop();
    int u = f.second;
    color[u] = black;

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

    for(int i = 0;i < W[u].size();i++) {
      int v = W[u][i].first;
      if(color[v] == black) continue;
      if(d[v] > d[u] + W[u][i].second) {
        d[v] = d[u] + W[u][i].second;
        PQ.push(make_pair(d[v] * (-1),v));
      }
    }
  }

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

int main() {

  cin >> n;
  

  for(int i = 0;i < n;i++) {
    int u,k;
    cin >> u >> k;
    color[i] = white;
    d[i] = INF;
    for(int j = 0;j < k;j++) {
      int v,c;
      cin >> v >> c;
      W[u].push_back(make_pair(v,c));
    }
  }

  dijkstra(0);

}