Go: package main

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

type Node struct {
	Id int
	Dis int
}

type PriorityQueue []*Node

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

func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].Dis < pq[j].Dis
}

func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
}

func (pq *PriorityQueue) Push(x interface{}) {
	*pq = append(*pq, x.(*Node))
}

func (pq *PriorityQueue) Pop() interface{} {
	n := len(*pq)
	pop := (*pq)[n-1]
	*pq = (*pq)[0:n-1]
	return pop
}

func main() {
	var n int
	fmt.Scan(&n)

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

	g := make([][]int, n)
	c := make([][]int, n)
	pq := make(PriorityQueue, 0, n)
	d := make([]int, n)
	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())
		g[u] = make([]int, k)
		c[u] = make([]int, k)
		for j := 0; j < k; j++ {
			sc.Scan()
			g[u][j], _ = strconv.Atoi(sc.Text())
			sc.Scan()
			c[u][j], _ = strconv.Atoi(sc.Text())
		}

		if u == 0 {
			d[u] = 0
		} else {
			d[u] = 1 << 30
		}
		pq.Push(&Node{u, d[u]})
	}
	heap.Init(&pq)

	for pq.Len() > 0 {
		node := heap.Pop(&pq).(*Node)
		for i := 0; i < len(g[node.Id]); i++ {
			nextId := g[node.Id][i]
			nextDis := node.Dis + c[node.Id][i]
			if nextDis < d[nextId] {
				d[nextId] = nextDis
				heap.Push(&pq, &Node{nextId, nextDis})
			}
		}
	}

	wr := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		wr.WriteString(strconv.Itoa(i))
		wr.WriteString(" ")
		wr.WriteString(strconv.Itoa(d[i]))
		wr.WriteString("\n")
	}
	wr.Flush()
}

C++: #include<stdio.h>
#include<queue>
#include<string.h>
using namespace std;
#define INF 1 << 30
struct ss{
	int next;
	int to;
	int val;
}e[200050];
int head[200050];
int tot;
void add(int x,int y,int val){
	e[tot].next=head[x];
	e[tot].to=y;
	e[tot].val=val;
	head[x]=tot++;
}
int n;
int vis[200000];
int dis[200050];
void spfa(){
	for(int i=0;i<n;i++){
		dis[i]=INF;
	}
	vis[0]=1;
	dis[0]=0;
	queue<int> st;
	st.push(0);
	while(!st.empty()){
		int t=st.front();
		st.pop();
		vis[t]=0;
		for(int i=head[t];i!=-1;i=e[i].next){
			int to=e[i].to;
			if(dis[to]>dis[t]+e[i].val){
				dis[to]=dis[t]+e[i].val;
				if(!vis[to]){
					st.push(to);
					vis[to]=1;
				}
			}
		}
	}
}
int main(){
	scanf("%d",&n);
	tot=0;
	memset(head,-1,sizeof(head));
	int a,to,val,num;
	for(int i=0;i<n;i++){
		scanf("%d %d",&a,&num);
		for(int j=1;j<=num;j++){
			scanf("%d %d",&to,&val);
			add(a,to,val);
		}
	}
	spfa();
	printf("0 0\n");
	for(int i=1;i<n;i++){
		printf("%d %d\n",i,dis[i]);
	}
	return 0;
}

C++: #include<cstdio>
#include<iostream>
#include<queue>
#include<algorithm>
#define Lens 10005
#define Inf 1<<22

using namespace std;
vector<pair<int, int> > adj[Lens];
int N;
char c[Lens];
int d[Lens];

void dijkstra()
{
	d[0] = 0;
	priority_queue<pair<int, int> > PQ;
	PQ.push(make_pair(0, 0));
	while (!PQ.empty())
	{
		pair<int, int> t = PQ.top();
		PQ.pop();
		int u = t.second;
		c[u] = 'b';
		if (d[u] < -t.first) continue;
		for (int i = 0; i < adj[u].size(); i++)
		{
			int tmp = adj[u][i].first;
			if (c[tmp] == 'w'&&d[tmp] > d[u] + adj[u][i].second)
			{
				d[tmp] = d[u] + adj[u][i].second;
				PQ.push(make_pair(-d[tmp],tmp));
				cout << tmp << "  " << d[tmp] << endl;
			}
		}

	}
}

int main()
{

	cin >> N;
	for (int i = 0; i < N; i++)
	{
		int k, n;
		cin >> k >> n;
		c[k] = 'w';
		d[k] = Inf;
		for (int j = 0; j < n; j++)
		{
			int v, tw;
			cin >> v >> tw;
			adj[k].push_back(make_pair(v, tw));
		}

	}
	dijkstra();
	for (int i = 0; i < N; i++)
	{
		cout << i << ' ' << d[i] << endl;;
	}
	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<queue>
#include<vector>
#include<utility>
#include<limits>
using namespace std;
typedef pair<int, int> Edge;
int main()
{
	int n; cin >> n;
	vector< vector< Edge > > lists;

	for (int i = 0; i < n; i++)
	{
		vector<Edge> list;
		int u, k;
		cin >> u >> k;
		for (int j = 0; j < k; j++)
		{
			Edge edge;
			cin >> edge.second >> edge.first;
			list.push_back(edge);
		}
		lists.push_back(list);
	}

	vector<int> costs(n, -1);
	costs[0] = 0;
	priority_queue<Edge> queue;
	queue.push(Edge(0, 0));

	while (!queue.empty())
	{
		Edge edge = queue.top(); queue.pop();
		int dest = edge.second;
		int cost = edge.first;
		if (costs[dest]<cost)continue;
		for (Edge next : lists[dest])
		{
			next.first += cost;
			if (costs[next.second] > next.first||costs[next.second]==-1)
			{
				costs[next.second] = next.first;
				queue.push(next);
			}
		}
	}
	for (int i = 0; i < n; i++)
		cout << i << " " << costs[i] << endl;

	char c;
	cin >> c;

	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

#define rep(i, a, b) for (int i = (a); i < (int)(b); i++)
#define rrep(i, a, b) for (int i = (a); i >= (int)(b); i--)
#define all(x) (x).begin(), (x).end()
using i32 = int32_t;
using i64 = int64_t;
using f32 = float;
using f64 = double;
using P   = pair<int, int>;

template <class T>
bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    } else {
        return false;
    }
}
template <class T>
bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    } else {
        return false;
    }
}

template <class T>
void dump_vec(const vector<T>& v) {
    auto len = v.size();
    rep(i, 0, len) {
        cout << v[i] << (i == (int)len - 1 ? "\n" : " ");
    }
}

struct FastIO {
    FastIO() {
        cin.tie(0);
        ios::sync_with_stdio(false);
        cout << fixed << setprecision(20);
    }
} FASTIO;

//---------------------------------------------------------------------------------------------------

struct Edge {
    int from, to;
    i64 cost;
    Edge() {}
    Edge(int t, i64 c) : from(-1), to(t), cost(c) {}
    Edge(int f, int t, i64 c) : from(f), to(t), cost(c) {}

    bool operator<(const Edge& r) const {
        return cost < r.cost;
    }
    bool operator>(const Edge& r) const {
        return cost > r.cost;
    }
};

using Vertex = vector<Edge>;
using Graph  = vector<Vertex>;

// 無向
void link(Graph& g, int from, int to, int cost = 1) {
    g[from].push_back(Edge(from, to, cost));
    g[to].push_back(Edge(to, from, cost));
    return;
}

// 有向
void connect(Graph& g, int from, int to, int cost = 1) {
    g[from].push_back(Edge(from, to, cost));
    return;
}

vector<i64> dijkstra(const Graph& g, int start) {
    const auto inf = numeric_limits<i64>::max();
    vector<i64> dist(g.size(), inf);

    using Pi = pair<i64, int>;
    priority_queue<Pi, vector<Pi>, greater<Pi>> que;
    dist[start] = 0;
    que.push(make_pair(0, 0));
    while (!que.empty()) {
        const auto e    = que.top();
        const auto cost = e.first;
        const auto from = e.second;
        que.pop();
        if (dist[from] < cost) continue;

        for (const auto& e : g[from]) {
            const auto next_cost = e.cost + cost;
            if (chmin(dist[e.to], next_cost)) {
                que.push(make_pair(next_cost, e.to));
            }
        }
    }

    return dist;
}

//---------------------------------------------------------------------------------------------------

signed main() {
    int N;
    cin >> N;
    Graph G(N);
    rep(i, 0, N) {
        int u, k;
        cin >> u >> k;
        rep(j, 0, k) {
            int v, c;
            cin >> v >> c;
            connect(G, u, v, c);
        }
    }
    auto dist = dijkstra(G, 0);
    rep(i, 0, N) {
        cout << i << " " << dist[i] << "\n";
    }
}