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++: #include <iostream>
#include <algorithm>
#include <vector>
#include <deque>
#include <queue>
#include <list>
#include <stack>
#include <string>
#include <tuple>
#include <functional>
#include <numeric>
#include <cmath>
#include <iomanip>
#include <map>
#include <random>
#include <cstdlib>
#define INT_MAX 2147483647
#define INT_MIN -2147483646
#define Loop(i, n) for(int i = 0; i < (int)n; i++)
#define Loop1(i, n) for(int i = 1; i <= (int)n; i++)
#define Loopr(i, n) for(int i = (int)n - 1; i >= 0; i--)
#define Loopr1(i, n) for(int i = (int)n; i >= 1; i--)
using namespace std;
typedef long long int ll;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;
void fastios() { ios_base::sync_with_stdio(0); cin.tie(0); }

static const int N = 10005;

struct vertex {
	int id;
	int p;
	int d;
	bool operator<(const vertex & another) const {
		return (d != another.d ? d>another.d : id>another.id);
	}
};

struct edge {
	int end;
	int w;
};

int main() {
	fastios();
	int n;
	cin >> n;
	vector<vector<edge>> E(N);
	Loop(i, n) {
		int u, k;
		cin >> u >> k;
		Loop(i, k) {
			int v, c;
			cin >> v >> c;
			E[u].push_back({ v,c });
		}
	}
	//
	priority_queue<vertex> pq;
	vi color(N, 0), dist(N, 0);
	pq.push({ 0,-1,0 });
	while (pq.size() > 0) {
		vertex v = pq.top();
		pq.pop();
		if (color[v.id] == 1) continue;
		dist[v.id] = v.d;
		color[v.id] = 1;
		Loop(j, E[v.id].size()) {
			pq.push({ E[v.id][j].end, v.id, dist[v.id] + E[v.id][j].w });
		}
	}
	Loop(i, n) {
		cout << i << " " << dist[i] << endl;
	}
	return 0;
}

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

typedef long long ll;
#define all(x) (x).begin(),(x).end()
const int mod=1000000007,MAX=100003;
const int INF=(1<<30);

int state[MAX],N,D[MAX];
vector<pair<int,int>> S[MAX];
priority_queue<pair<int,int>> Q;

void dijkstra(int u){
    int cnt=0;
    for(int i=0;i<N;i++){
        state[i]=0;
        D[i]=INF;
    }
    
    D[u]=0;
    Q.push(make_pair(0,u));
    
    while(1){
        int a=Q.top().second;
        Q.pop();
        if(state[a]==0){
            state[a]=1;
            for(int i=0;i<S[a].size();i++){
                if(state[S[a][i].first]==0){
                    Q.push(make_pair(-(D[a]+S[a][i].second),S[a][i].first));
                    D[S[a][i].first]=min(D[S[a][i].first],D[a]+S[a][i].second);
                }
            }
            cnt++;
        }
        if(cnt==N) break;
    }
    return;
}


int main(){

    cin>>N;
    for(int i=0;i<N;i++){
        int l,a;cin>>l>>a;
        for(int j=0;j<a;j++){
            int b,c;cin>>b>>c;
            S[i].push_back(make_pair(b,c));
        }
    }
    dijkstra(0);
    for(int i=0;i<N;i++){
        cout<<i<<" "<<D[i]<<endl;
    }
}

C++: #include<iostream>
#include<iomanip>
#include<algorithm>
#include<bitset>
#include<cctype>
#include<cmath>
#include<cstdio>
#include<cstring>
#include<functional>
#include<limits>
#include<list>
#include<map>
#include<set>
#include<stack>
#include<string>
#include<sstream>
#include<queue>
#include<vector>
using namespace std;

#define MOD 1000000007
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3fLL

#define MAX 10000
#define WHITE 0
#define GRAY 1
#define BLACK 2

typedef pair<int, int> pii;

struct edge { int to, c; };
vector<edge> G[MAX];
int color[MAX] = {};//WHITE

int n;

void dijkstra() {
	priority_queue<pii, vector<pii>, greater<pii> >PQ; //minc v
	int color[MAX] = {};
	int	minc[MAX];
	fill(minc, minc + MAX, INF);
	minc[0] = 0;

	//?§????????????\
	PQ.push(pii(0, 0));
	color[0] = GRAY;

	//PQ???????´????????????°
	while (!PQ.empty()) {
		//minc???????°??????¨??????????´????????????????
		pii p = PQ.top(); PQ.pop();

		int u = p.second;
		color[u] = BLACK;

		//????????§???????????°??????
		if (minc[u] < p.first) { continue; }

		//??£??\????????????????????¨????????????
		for (int j = 0; j < G[u].size(); j++) {
			edge e = G[u][j];
			if (color[e.to] == BLACK)continue;
			if (minc[e.to] > minc[u] + e.c) {
				minc[e.to] = minc[u] + e.c;
				PQ.push(pii(minc[e.to], e.to));
				color[e.to] = GRAY;
			}
		}
	}
	for (int i = 0; i < n; i++) {
		cout << i << " " << (minc[i] == INF ? -1 : minc[i]) << endl;
	}
}

int main() {
	cin >> n;
	for (int i = 0; i < n; i++) {
		int u, k; scanf("%d%d", &u, &k);
		for (int j = 0; j < k; j++) {
			int v, c; scanf("%d%d", &v, &c);
			edge e; e.to = v; e.c = c;
			G[u].push_back(e);
		}
	}
	dijkstra();
	return 0;
}