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 <iostream>
#include <algorithm>
#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;
vector<pair<int, int> > adj[MAX];

void dijkstra() {
	priority_queue<pair<int, int> > PQ;
	int color[MAX];
	int d[MAX];
	for (int i = 0; i < n; i++) {
		d[i] = INFTY;
		color[i] = WHITE;
	}

	d[0] = 0;
	PQ.push(make_pair(0, 0));
	color[0] = GRAY;

	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 j = 0; j < adj[u].size(); j++) {
			int v = adj[u][j].first;
			if (color[v] == BLACK)continue;
			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));
				color[v] = GRAY;
			}
		}
	}
	for (int i = 0; i < n; i++) {
		cout << i << " " << (d[i] == INFTY ? -1 : d[i]) << "\n";
	}
}

int main() {
	int k, u, v, c;
	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 INF 1e9
using namespace std;
typedef pair<uint32_t,uint32_t> P;

int bitSearchReverse(uint32_t x){
    if(x==0)return -1;
    return 31-__builtin_clz(x);
}
struct RadixHeap{
    vector<P>v[33];
    uint32_t last,sz;
    RadixHeap(){
        last=sz=0;
    }
    void push(P p){
        assert(last<=p.first);
        sz++;
        v[bitSearchReverse(p.first^last)+1].push_back({p.first,p.second});
    }
    P top(){
        return pop(false);
    }
    P pop(bool f=true){
        assert(sz);
        if(!v[0].size()){
            int i=1;
            while(!v[i].size())++i;
            last=min_element(v[i].begin(),v[i].end())->first;
            for(P p:v[i])v[bitSearchReverse(p.first^last)+1].push_back(p);
            v[i].clear();
        }
        P r=v[0].back();
        if(f){
            sz--;
            v[0].pop_back();
        }
        return r;
    }
    int size(){
        return sz;
    }
    bool empty(){
        return sz==0;
    }
    void clear(){
        last=sz=0;
        for(auto a:v)a.clear();
    }
};
struct Graph{
    Graph(int n):E(n),d(n){}
    vector<vector<P>>E;
    vector<uint32_t>d;
    void add_edge(int a,int b,uint32_t c){
        E[a].emplace_back(b,c);
    }
    void dijkstra(int s){
        RadixHeap H;
        fill(d.begin(),d.end(),INF);
        H.push({d[s]=0,s});
        while(H.size()){
            P e=H.top();H.pop();
            if(e.first>d[e.second])continue;
            for(P& a:E[e.second]){
                uint32_t x=a.first,y=a.second+e.first;
                if(y<d[x])d[x]=y,H.push({y,x});
            }
        }
    }
};

main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int N;
    cin>>N;
    Graph G(N);
    for(int i=0;i<N;++i){
        int u,k;
        cin>>u>>k;
        for(int j=0;j<k;++j){
            int v,c;
            cin>>v>>c;
            G.add_edge(u,v,c);
        }
    }
    G.dijkstra(0);
    for(int i=0;i<N;++i)
        cout<<i<<' '<<G.d[i]<<endl;
}

/***************************************

referred
https://github.com/yosupo06/Algorithm/blob/master/datastructure/buf/RadixHeap.h

****************************************/

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

using namespace std;
const int INF = 1e18;

struct edge
{
    int to;
    int cost;
};
using Graph = vector<vector<edge>>;

#define WHITE 0
#define GRAY 1
#define BLACK 2

int n;
Graph G;

void dijkstra(int start)
{
    int seen[10010];
    int dist[10010];

    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
    for (int i = 0; i < n; i++)
    {
        seen[i] = (i == start) ? GRAY : WHITE;
        dist[i] = (i == start) ? 0 : INF;
        pq.push(make_pair(dist[i], i));
    }

    while (!pq.empty())
    {
        auto now = pq.top();
        pq.pop();
        int u = now.second;
        int distU = now.first;

        seen[u] = BLACK;

        for (auto ne : G[u])
        {
            int v = ne.to;
            int cv = ne.cost;
            if (dist[u] + cv < dist[v])
            {
                dist[v] = dist[u] + cv;
                pq.push(make_pair(dist[v], v));
                seen[v] = GRAY;
            }
        }
    }

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

void solve()
{

    // remove the bottom 3 lines when you submit this code.
    std::ifstream in("sample.txt");
    std::cin.rdbuf(in.rdbuf());

    cin.tie(0);
    ios::sync_with_stdio(false);

    cin >> n;
    G.resize(n);

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

    dijkstra(0);
}

signed main()
{
    solve();
    return 0;
}