Go: package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
)

type Item struct {
	value    int // The value of the item; arbitrary.
	priority int // The priority of the item in the queue.
	// The index is needed by update and is maintained by the heap.Interface methods.
	index int // The index of the item in the heap.
}
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }
func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].priority < pq[j].priority
}
func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = i
	pq[j].index = j
}
func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}
func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	item.index = -1 // for safety
	*pq = old[0 : n-1]
	return item
}

type Q struct {
	pq *PriorityQueue
	ds map[int]int // It has always same value as pq. For random access.
}

func newQ() *Q {
	pq := new(PriorityQueue)
	heap.Init(pq)
	return &Q{
		pq: pq,
		ds: make(map[int]int),
	}
}
func (q *Q) pop() (u, d int) {
	item := heap.Pop(q.pq).(*Item)
	delete(q.ds, item.value)
	return item.value, item.priority
}
func (q *Q) get(u int) (int, bool) { // returns d
	d, ok := q.ds[u]
	return d, ok
}
func (q *Q) set(u, d int) {
	q.ds[u] = d
	for _, item := range *q.pq {
		if item.value != u {
			continue
		}

		item.priority = d
		heap.Fix(q.pq, item.index)
		return
	}
	heap.Push(q.pq, &Item{
		priority: d,
		value:    u,
	})
}
func (q *Q) len() int {
	return len(q.ds)
}

func main() {
	r := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(r, &n)
	cs := make([]map[int]int, n) // []v_i -> c_i
	for h := 0; h < n; h++ {
		var u, k int
		fmt.Fscan(r, &u, &k)
		m := make(map[int]int)
		for i := 0; i < k; i++ {
			var v, c int
			fmt.Fscan(r, &v, &c)
			m[v] = c
		}

		cs[u] = m
	}

	q := newQ()
	q.set(0, 0)
	visited := make(map[int]struct{})
	out := make([]int, n)

	for q.len() > 0 {
		u, d := q.pop()
		for uu, c := range cs[u] {
			// Consider the connection between u and uu.
			if _, ok := visited[uu]; ok {
				continue
			}
			dd := d + c
			if d, ok := q.get(uu); !ok || d > dd {
				q.set(uu, dd)
			}
		}

		out[u] = d
		visited[u] = struct{}{}
	}

	for u, d := range out {
		fmt.Println(u, d)
	}
}

C++: // 単一始点最短経路 ( ダイクストラ法 : 優先度付きキュー )
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<stack>
#include<algorithm>
#include<iostream>
#include<cmath>
#include<vector>

#include<queue>

using namespace std;

static const int MAX = 10000;
static const int INFTY = (1 <<20);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;

// 重み付き有向グラフの隣接リスト表現
// first : 頂点No. second : 入力される辺の重み
vector< pair<int, int> > adj[MAX];

int Dijkstra()
{
    int u;
    int d[MAX], p[MAX], color[MAX];

    // 優先度付きキュー : first : 最短距離 second : 頂点No.
    priority_queue< pair<int, int> > PQ;

    for(int i = 0; i < n; i++)
    {
        d[i] = INFTY;
        p[i] = -1;
        color[i] = WHITE;
    }

    // 初期値の設定
    d[0] = 0;
    PQ.push( make_pair(0, 0) );
    color[0] = GRAY;

    while( !PQ.empty() )
    {
        pair<int, int> f = PQ.top();
        PQ.pop();

        // 次に移動するべき頂点
        u = f.second;;
        // 訪問完了
        color[u] = BLACK;

        // 最小値を取り出し, それが最短で無ければ無視
        if( d[u] < f.first * (-1) )
        {
            continue;
        }

        for(int j = 0; j < adj[u].size(); j++)
        {
            // 隣接リストから要素を取得する
            int v = adj[u][j].first;

            if( color[v] != BLACK )
            {
                // u → v の経路の中で, vのコストが最小のものが見つかれば更新する
                if( d[v] > d[u] + adj[u][j].second )
                {
                    // コストの記録
                    d[v] = d[u] + adj[u][j].second;
                    // 頂点 v の親を記録する
                    p[v] = u;
                    // 訪問状態の記録
                    color[v] = GRAY;

                    // キューに要素を入れる
                    // 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 ) );
                }
            }
        }
    }

    // 結果の表示
    for(int i = 0; i < n; i++)
    {
        cout << i << " " << ( d[i] == INFTY ? -1 : d[i] ) << endl;
    }

    return 0;
}

int main(void)
{

    int k, c, u, v;

    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<bits/stdc++.h>
#define REP(i,n) for(int i=0;i<(int)(n);i++)
using namespace std;

struct edge { int from, to, cost; };
const int MAX_V=100;
const int INF=1e9;

vector<edge> es;
int d[MAX_V];
int n;

void shortest_path(int s){
  REP(i, n) d[i] = INF;
  d[s] = 0;
  while(true){
    bool update = false;
    for(edge e : es){
      if(d[e.from] != INF && d[e.to] > d[e.from] + e.cost){
	d[e.to] = d[e.from] + e.cost;
	update = true;
      }
    }
    if(!update) break;
  }
}

int main(){
  cin>>n;
  REP(i,n){
    int u, k; cin>>u>>k;
    REP(j,k){
      edge e;
      e.from = u;
      cin>>e.to>>e.cost;
      es.push_back(e);
    }
  }
  shortest_path(0);
  REP(i,n){
    cout<<i<<" "<<d[i]<<endl;
  }
}