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<climits>
using namespace std;

typedef struct{
  int A[10010];
  int ans;
}node;
node T[10010];
int Q[10000003];
int head=0;
int tail=1;
int n;

void function(int num){
  while(true){
    if(head==tail)break;
    num=Q[head++];
        if(head==9999999)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==9999999)tail=1;
	}
      }
    }
  }
}

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++){
    cin>>num>>son;
    T[num].ans=INT_MAX;
    for(int j=0;j<son;j++){
      cin>>z>>w;
      T[num].A[z]=w;
      }
  }
  Q[0]=0;
  T[0].ans=0;
  function(0);
 
  for(int i=0;i<n;i++){
      cout<<i<<" "<<T[i].ans<<endl;
  }
  return 0;
}

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

#define REP(i, n) for(int i=0;i<(int)(n);i++)
#define ALL(x) (x).begin(),(x).end()
const int INF = 1e9;

using namespace std;
int n;
int res = 0;
struct node {
    int id;
    int dist;
    bool searched;
};

node v[10000];
int edge[10000][10000];

int main() {
    cin >> n;
    REP(i, n) {
        int u, k;
        cin >> u >> k;
        v[u].id = u;
        v[u].dist = INF;
        v[u].searched = false;
        REP(j, n) edge[i][j] = INF;
        REP(j, k){
            int to, cost;
            cin >> to >> cost;
            edge[i][to] = cost;
        }
    }
    v[0].dist = 0;
    int prev = 0;
    REP(i, n){
        int minimum = INF;
        REP(j, n){
            if(!v[j].searched && minimum >= v[j].dist){
                prev = j;
                minimum = v[j].dist;
            }
        }
        REP(j, n){
            if(!v[j].searched && edge[prev][j] != INF){
                v[j].dist = min(v[j].dist, v[prev].dist + edge[prev][j]);
            }
        }
        v[prev].searched = true;
    }
    REP(i, n) cout << i << " " << v[i].dist << endl;
    return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<string>
#include<algorithm>
#include<vector>
#include<queue>
#include<functional>
#include<map>
#include<cstring>
#define P pair<int,int>//cost to
using namespace std;

vector<P>rinsetu[10000];
int mincost[10000];
signed main() {
	int a; cin >> a;
	for (int b = 0; b < a; b++) {
		int c, d; cin >> c >> d;
		for (int e = 0; e < d; e++) {
			int f, g; scanf("%d%d", &f, &g);
			rinsetu[c].push_back(P(g,f));
		}
	}
	fill(mincost, mincost + a, 1 << 29);
	mincost[0] = 0;
	priority_queue<P, vector<P>, greater<P>>Q;
	Q.push(P(0,0));
	while (Q.size()) {
		P t = Q.top(); Q.pop();
		if (t.first > mincost[t.second])continue;
		for (P i : rinsetu[t.second]) {
			if (mincost[i.second] > t.first + i.first) {
				mincost[i.second] = t.first + i.first;
				Q.push(P(t.first + i.first,i.second));
			}
		}
	}
	for (int i = 0; i < a; i++) {
		cout << i << " " << mincost[i] << endl;
	}
}

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

using namespace std;
static const int MAX=10000;
static const int INFTY = (1<<21);

vector< pair<int,int> >M[MAX]; //?????\??¨
priority_queue< pair<int,int> > PQ; //????????§??????, first???d[i], second???i??? ?????¨??¶?????????first???????????°
bool visited[MAX]; //???????¢??????????
int d[MAX]; //?????????????????¬

void dijkstra_implementsPQ(int n)
{
    //init
    for(int i=0;i<n;i++)
    {
        d[i]=INFTY;
        visited[i]=false;
    }
    //select node 0
    d[0]=0;
    PQ.push(make_pair(0,0));

    while(!PQ.empty())
    {
        //currently the top of PQ is the shortest one
        pair<int,int> temp=PQ.top();PQ.pop();
        int u=temp.second;

        visited[u]=true;
        if(d[u]<temp.first*(-1)) continue;

        //update
        for(int j=0;j<M[u].size();j++)
        {
            int v=M[u][j].first;
            if(visited[v]==true) continue;
            //else try updating
            if(d[v]>d[u]+M[u][j].second)
            {
                d[v]=d[u]+M[u][j].second;
                PQ.push(make_pair(d[v]*(-1),v));
            }
        }
    }
    //print
    for(int i=0;i<n;i++)  cout<<i<<' '<<(d[i]==INFTY?-1:d[i])<<endl;

}
int main()
{
    int n;
    cin>>n;

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

    dijkstra_implementsPQ(n);
}