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<stdio.h>
#include<stdlib.h>

#define INF 100000000

typedef struct state{
  int pos,cost;
} state;

state A[2000001];
int N=0;

int parent(int i){return i/2;}
int left(int i){return i*2;}
int right(int i){return i*2+1;}

void exchange(state* a, state* b){
  state tmp=*a;
  *a=*b;
  *b=tmp;
}

void minHeapify(int i){
  int l=left(i);
  int r=right(i);
  int small;

  if( l<=N && A[l].cost<A[i].cost )small=l;
  else small=i;

  if( r<=N && A[r].cost<A[small].cost)small=r;

  if(small!=i){
    exchange(&A[i],&A[small]);
    minHeapify(small);
  }

}

state heapExtractMin(){
  if(N<1)return (state){0,0};
  state min=A[1];
  A[1]=A[N];
  N--;
  minHeapify(1);
  return min;
}


void heapIncreaseKey(int i, state key){
  if(key.cost>A[i].cost)return;

  A[i]=key;
  while(i>1&&A[parent(i)].cost>A[i].cost){
    exchange(&A[i],&A[parent(i)]);
    i=parent(i);
  }
}

void minHeapInsert(state key){
  N++;
  A[N]=(state){INF, INF};
  heapIncreaseKey(N, key);
}


typedef struct edge{
  int to,cost;
} edge;

edge* G[10000];
int size[10000];
int n;
int d[10000];
edge e;
state s;

int main(){

  int i, j, a, b;

  scanf("%d", &n);

  for(i=0; i<n; i++){
    scanf("%d %d", &a, &b);
    G[a] = malloc( sizeof( edge ) *b );
    size[a]=b;
    for(j=0; j<b; j++){
      scanf("%d %d",&G[a][j].to, &G[a][j].cost);
    }
    d[i]=INF;
  }

  d[0]=0;
  minHeapInsert( (state){0, 0} );

  while(N!=0){
    s = heapExtractMin();
    if(s.cost>d[s.pos])continue;
    for(i=0;i<size[s.pos];i++){
      e=G[s.pos][i];
      if(d[e.to]<=d[s.pos]+e.cost)continue;
      d[e.to]=d[s.pos]+e.cost;
      minHeapInsert((state){e.to, d[e.to]});
    }
  }

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

  return 0;
}

C++: #include <iostream>
#include <set>
#include <vector>
#include <queue>
#include <stack>
#include <utility>
#include <algorithm>

using namespace std;

typedef long long signed int ll;

constexpr ll NIL = -20000000000;

class path{
public:
    int from;
    int to;
    int dist;
    path(){
        from = -1;
        to = -1;
        dist = -1;
    }
    path(int from_,int to_,int dist_){
        from = from_;
        to = to_;
        dist = dist_;
    }
    static bool compare(const path& a,const path& b) {
        return a.from < b.from;
    }
    bool operator<(const path& e) const {
        return this->dist < e.dist;
    }
};

int n,u,k,v,c;
vector<path> w;
ll d[10000];
bool dd[10000];

int main() {
    for(int i = 0;i < 10000;i++)d[i] = -NIL;
    for(int i = 0;i < 10000;i++)dd[i] = false;
    cin >> n;
    for(int i = 0;i < n;i++) {
        cin >> u >> k;
        for(int j = 0;j < k;j++) {
            cin >> v >> c;
            w.push_back(path(u,v,c));
        }
    }
    sort(w.begin(),w.end(),path::compare);
    priority_queue<pair<int,int>> q;
    q.push(make_pair(0,0));
    d[0] = 0;
    while(!q.empty()) {
        auto y = q.top();q.pop();
        if(dd[y.second]) continue;
        dd[y.second] = true;
        auto r = lower_bound(w.begin(),w.end(),path(y.second,0,0),path::compare);
        auto l = lower_bound(w.begin(),w.end(),path(y.second+1,0,0),path::compare);
        for(auto itr = r;itr < l;itr++) {
            if(d[itr->to] > d[itr->from] + itr->dist) {
                d[itr->to] = d[itr->from] + itr->dist;
                q.push(make_pair(d[itr->to],itr->to));
            }
        }
    }
    for(int i = 0;i < n;i++){
        cout << i << " " << d[i] << endl;
    }
}

C++: #include <iostream>
#include <queue>
#include <vector>
#include <utility>
using namespace std;
typedef pair<int, int> P;
struct edge {int to, cost;};
const int INF = 2100000000;
int n;
vector<edge> G[110];


vector<int> dijkstra(int s) {
    priority_queue<P, vector<P>, greater<P>> que;
    que.push(P(0, s));
    vector<int> d(n, INF);
    d[s] = 0;
    while (!que.empty()) {
        P p = que.top(); que.pop();
        int v = p.second;
        if (d[v] < p.first) continue;
        for (auto e: G[v]) {
            if (d[e.to] > d[v] + e.cost) {
                d[e.to] = d[v] + e.cost;
                que.push(P(d[e.to], e.to));
            }
        }
    }
    return d;
}

int main(void) {
    cin >> n;
    for (int i = 0; i < n; i++) {
        int u, k, v, c;
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            cin >> v >> c;
            G[u].push_back(edge {v, c});
        }
    }
    vector<int> d = dijkstra(0);
    for (int i = 0; i < n; i++) {
        cout << i << " " << d[i] << endl;
    }

    return 0;
}