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

	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++: #define _CRT_SECURE_NO_WARNINGS
// #define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
template<class T> ostream &operator << (ostream &os, const vector<T> &);
template<size_t n, class...T> typename enable_if<(n>=sizeof...(T))>::type _ot(ostream &, const tuple<T...> &){}
template<size_t n, class...T> typename enable_if<(n< sizeof...(T))>::type _ot(ostream &os, const tuple<T...> &t){
    os << (n == 0 ? "" : " ") << get<n>(t); _ot<n+1>(os, t);
}
template<class...T> ostream &operator << (ostream &os, const tuple<T...> &t){
    _ot<0>(os, t); return os;
}
template<class T, class U> ostream & operator << (ostream &os, const pair<T,U> &p){
    return os << "(" << p.first << ", " << p.second << ") ";
}
template<class T> ostream &operator << (ostream &os, const vector<T> &v){
    for(size_t i = 0; i < v.size(); i++) os << v[i] << (i + 1 == v.size() ? "" : ", "); return os;
}
#ifdef DEBUG
#define dump(...) (cerr << #__VA_ARGS__ << " = " << make_tuple(__VA_ARGS__) \
                   << " (L : " << __LINE__ << ")" << endl)
#else
#define dump(...)
#endif
#define all(c) begin(c), end(c)
#define range(i,a,b) for(int i = a; i < (int)(b); i++)
#define rep(i,b) range(i,0,b)
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define mt make_tuple
using ll = long long;
// #define int ll
using vi = vector<int>;
using vvi = vector<vi>;
using pii = pair<int,int>;
void fastios(){ ios_base::sync_with_stdio(0); cin.tie(0); }
int const mod = 1000000007;
auto const inf = numeric_limits<int>::max()/8;

using Weight = int;
using Capacity = int;
struct Edge {
    int src, dst; Weight weight;
    Edge(int s, int d, int w) : src(s), dst(d), weight(w) {}
};
using Edges = vector<Edge>;
using Graph = vector<Edges>;
using Array = vector<Weight>;
using Matrix = vector<Array>;

vector<Weight> dijkstra(const Graph &g, int s){
    const Weight inf = numeric_limits<Weight>::max()/4;
    typedef tuple<Weight,int> State;
    priority_queue<State> q;
    vector<Weight> dist(g.size(), inf);
    dist[s] = 0; q.emplace(0,s);
    while (q.size()) {
        Weight d; int v;
        tie(d,v) = q.top(); q.pop(); d *= -1;
        /* if(v == t) return d; */
        if (dist[v] < d) continue;
        for(auto & e : g[v]){
            if (dist[e.dst] > dist[v] + e.weight) {
                dist[e.dst] = dist[v] + e.weight;
                q.emplace(-dist[e.dst], e.dst);
            }
        }
    }
    return dist;
}


int main(){
    fastios();
    int n;
    cin >> n;
    Graph g(n);
    rep(i,n){
        int u,k;
        cin >> u >> k;
        rep(j,k){
            int v,c;
            cin >> v >> c;
            g[u].eb(u,v,c);
        }
    }
    auto dist = dijkstra(g,0);
    rep(i,n){
        cout << i << ' ' << dist[i] << '\n';
    }
}

C++: #include<iostream>
using namespace std;
#include<queue>
#include<vector>
#include<string>
#include<string.h>
#include<algorithm>
bool b[2003];

#define REP(i, a) for(int i=0;i<a;i++)

int main()
{
	int min,b,a,k,m[101][101],n ,e,p[101],d[101],u,v; //u ?????????v????????¨
	bool color[101];
	cin>>n;
	REP(i, n) {
		REP(j, n) {
		m[i][j]=100001;
		}
	}
	REP(i, n) {
		cin>>u>>k;
		REP(i, k) {
			cin>>a>>b;
			m[u][a]=b;
			if(m[u][a]==-1) m[u][a]=100001;
		}
		color[i]=0;
		d[i]=100001;
	}
	a=0;
	d[0]=0;
	while(1){
		min=100001;
		u=-1;
		REP(i,n){
			if(min>d[i]&&color[i]==0){
				min=d[i];
				u=i;
			}
		}
		if(u==-1) break;
		color[u]=1;
		REP(i,n){
			if(color[i]==0&&m[u][i]!=100001){
				if(d[i]>m[u][i]+d[u]){
					d[i]=m[u][i]+d[u];
				}
			}
		}

	}
	min=0;
	REP(i,n){
		cout<<i<<" "<<(d[i] == 100001 ? -1 : d[i])<<endl;
	
	}
	return 0;
}

C++: #include <cmath>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <climits>
#include <map>
#include <list>
#include <stack>
#include <queue>
#include <vector>
#include <string>
#include <sstream>
#include <fstream>
#include <iostream>
#include <algorithm>
using namespace std;

struct node {
	int id;
	int cost;
	node(int i, int c){
		this->id = i;
		this->cost = c;
	}
	bool operator<(node c) const {
		return this->cost > c.cost;
	}
};

int main() {
	int n;
	scanf("%d", &n);
	
	int c[n];
	int w[n][n];
	for(int i = 0; i < n; i++){
		int u, k;
		scanf("%d %d", &u, &k);
		
		c[u] = u ? INT_MAX : 0;
		for(int j = 0; j < n; j++){
			w[u][j] = -1;
		}
		while(k--){
			int v, c;
			scanf("%d %d", &v, &c);
			w[u][v] = c;
		}
	}
	
	priority_queue<node> q;
	q.push(*new node(0, 0));
	while(q.size()){
		int i = q.top().id;
		int ca = q.top().cost;
		q.pop();
		
		for(int j = 0; j < n; j++){
			if(w[i][j] != -1 && c[j] > w[i][j] + ca){
				c[j] = w[i][j] + ca;
				q.push(*new node(j, c[j]));
			}
		}
	}
	
	for(int i = 0; i < n; i++){
		printf("%d %d\n", i, c[i]);
	}
}

C++: #include <iostream>
#include <cstdio>
#include <string>
#include <list>
#include <stack>
#include <queue>
#include <algorithm>
#include <utility>
#include <vector>
#include <map>
#include <bitset>

using namespace std;

int main()
{
	int N;
	cin>>N;
	
	vector<vector<int> > cost(N,vector<int>(N,10000001));
	cost[0][0]=0;
	pair<int,int> ddata;
	for(int i=0;i<N;i++){
		int u,k;
		cin>>u>>k;
		for(int j=0;j<k;j++){
			cin>>ddata.first>>ddata.second;
			cost[u][ddata.first]=ddata.second;
		}
	}
	//
	
	vector<int> maxcost(N,10000001);
	
	priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>> > que;
	
	que.push(pair<int,int>(0,0));
	
	while(!que.empty()){
		int n=que.top().second;
		if(que.top().first<maxcost[n]){
			maxcost[n]=que.top().first;
		}
		for(int j=1;j<N;j++){
			if(que.top().first+cost[n][j]<maxcost[j]){
				maxcost[j]=que.top().first+cost[n][j];
				ddata.first=que.top().first+cost[n][j];
				ddata.second=j;
				que.push(ddata);
			}
		}
		que.pop();
	}
	
	for(int i=0;i<N;i++){
		cout<<i<<' '<<maxcost[i]<<endl;
	}
	return 0;
}