Go: package main

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

//make priority queue
type Item struct {
	id       int
	priority int // this state is priority and distans from start
	index    int
}

type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }

// we want the ascending-priority-queue.
// So we use less than here.
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 = j
	pq[j].index = i
}

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
}

func (pq *PriorityQueue) update(dist int, id int) {
	for _, i := range *pq {
		if i.id == id {
			if i.priority > dist {
				i.priority = dist
			}
		}
	}
}

// the main code
func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())
	return n
}

func dikstra(dist [][]int, n int) []int {
	// preparate priority queue
	inf := 1 << 30
	pq := make(PriorityQueue, n)
	shortests := make([]int, n)
	for i := 0; i < n; i++ {
		pq[i] = &Item{
			id:       i,
			priority: inf,
			index:    i,
		}

		shortests[i] = inf
	}
	pq[0].priority = 0
	shortests[0] = 0
	heap.Init(&pq)

	for pq.Len() > 0 {
		item := heap.Pop(&pq).(*Item)
		shortests[item.id] = item.priority
		for id, d := range dist[item.id] {
			if d != -1 {
				pq.update(item.priority+d, id)
			}
		}
		heap.Init(&pq)
	}
	return shortests
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	// init
	n := nextInt(sc)
	dist := make([][]int, n)
	for i := 0; i < n; i++ {
		dist[i] = make([]int, n)
		for j := 0; j < n; j++ {
			dist[i][j] = -1
		}
	}

	// std Input
	for i := 0; i < n; i++ {
		u := nextInt(sc)
		k := nextInt(sc)
		for j := 0; j < k; j++ {
			v, c := nextInt(sc), nextInt(sc)
			dist[u][v] = c
		}
	}

	shortests := dikstra(dist, n)
	for i, d := range shortests {
		fmt.Printf("%d %d\n", i, d)
	}
}

C++: #include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;i++)
#define all(x) (x).begin(),(x).end()
using namespace std;
const int INF=1145141919,MOD=1e9+7;
const long long LINF=8931145141919364364,LMOD=998244353;
// const int dx[]={1,0,-1,0,1,1,-1,-1},dy[]={0,-1,0,1,1,-1,-1,1};

const int VMAX=100010;
int V,E,start,goal;
vector<pair<long long,int>> edge[VMAX];
long long dist[VMAX];
bool used[VMAX];

void dijkstra(){
    // 距離をLINFで初期化
    rep(to,VMAX) dist[to]=LINF;
    // 始点は0
    dist[start]=0;
    // フラグを下げる
    rep(v,VMAX) used[v]=false;
    // 優先度付きキュー:[距離,頂点]←距離の昇順
    priority_queue<pair<long long,int>,vector<pair<long long,int>>,greater<pair<long long,int>>> q;
    // 距離0,始点
    q.push({0,start});
    // dijkstra
    while(q.size()){
        // 取り出してd=距離,v=頂点
        pair<long long,int> p=q.top(); q.pop();
        long long d=p.first;
        int from=p.second;
        if(used[from]) continue;
        used[from]=true;
        // 頂点から出る辺すべてについて
        for(auto e:edge[from]){
            long long cost=e.first,to=e.second;
            // 短縮できるとき
            if(d+cost<dist[to]){
                dist[to]=d+cost;
                q.push({dist[to],to});
            }
        }
    }
}

int main(){
    cin>>V;
    rep(i,V){
        int u,k; cin>>u>>k;
        rep(j,k){
            int to,distance;
            cin>>to>>distance;
            edge[u].push_back({distance,to});
        }
    }
    start=0;
    dijkstra();
    rep(i,V){
        cout<<i<<" "<<dist[i]<<endl;
    }
    return 0;
}