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 <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]) << endl;
	}
}

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<iostream>
#include<cstdio>
#include<vector>
#include<queue>
#include<map>
#include<string>
#include<algorithm>
#include<functional>
#define ll long long
#define inf  999999999
#define pa pair<int,int>

using namespace std;

int n;
vector<pa> a[10200];
void dij(){
	int d[10200]={0};
	int ans[10200]={0};
	priority_queue<pair<int,pa> >  PQ; 
	pair<int,pa> q;
	pa r;
	int wei=0;
	int u=0,z=0;
	d[0]=1;
	while(z!=n-1){
		for(int j=0;j<a[u].size();j++){
			q=make_pair(a[u][j].second,make_pair(u,a[u][j].first));
			if(d[a[u][j].first]==0 ) PQ.push(q);
		}
	while(1){
		if(PQ.size()==0) {
			cout<<"dv"<<endl;
		break;
		}
		q=PQ.top();
		PQ.pop();
		r=q.second;
	//	cout<<"rsec"<<r.second<<endl;
		if(d[r.second]==0) break;
		cout<<q.first<<endl;
		}
	u=r.second;
//	cout<<"a" <<u<<endl;
	d[u]=1;
	ans[u]=ans[r.first]+q.first;
	wei=wei+q.first;
	z++;
//	cout<<z<<" "<<-q.first<<" "<<u<<" "<<r.first<<endl;
	
	}
//	cout<<-wei<<endl;
	for(int i=0;i<n;i++) cout<<i<<" "<<-ans[i]<<endl;
}



int main(){
	// your code goes here
	int m,k,z,l;
	cin>>n;
	for(int i=0;i<n;i++){
	cin>>z>>k;
	
		for(int j=0;j<k;j++){
		cin>>m>>l;
		a[i].push_back(make_pair(m,-l));
		}
	}
	dij();

	return 0;
}

C++: #define RangeFor(i,n) for(int i=0; i<n; ++i)
#define RvRngFor(i,n) for(int i=n-1; i>=0; --i)

#include <iostream>
#include <vector>
#include <queue>
#include <utility>
#include <numeric>

using std::vector;
using std::cin;
using std::priority_queue;
using std::pair;
using std::make_pair;


vector<int> sssp(vector<vector<pair<int, int> > > c, int start_node = 0){
    int n = c.size();
    priority_queue<pair<int, int>, vector<pair<int,int> >, std::greater<pair<int, int>> > pq;
    vector<int> temp_dist(n, 100000000);
    pq.push(make_pair(0, start_node));

    for(;!pq.empty();pq.pop()){
        auto t = pq.top();
        auto d = t.first;
        auto u = t.second;


        if(d < temp_dist[u]){
            temp_dist[u] = d;
            auto k = c[u].size();
            RangeFor(j, k) {
                pq.push(make_pair(d + c[u][j].second, c[u][j].first));
            }
        }
    }

    return temp_dist;
}

int main(){
    int n; cin >> n;
    vector<vector< pair<int,int> > > c(n);
    RangeFor(i, n) {
        int u;
        cin >> u;
        int k;
        cin >> k;
        c[u] = vector<pair<int, int> >(k);
        RangeFor(j, k) {
            int v;
            cin >> v;
            int d;
            cin >> d;
            c[u][j] = make_pair(v, d);
        }
    }

//    RangeFor(i, n){
//        RangeFor(j, c[i].size()){
//            std::cout << c[i][j].first << ' ' << c[i][j].second;
//        }
//        std::cout << std::endl;
//    }
    
    auto res = sssp(c);
    RangeFor(i, n){
        std::cout << i << ' ' << res[i] << std::endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
int main(void){
    int n,i,j;
    cin>>n;
    vector<bool> used(n,false);
    vector<int> dist(n,99999999);
    vector<vector<pair<int,int>>> v(n);
    for(i=0;i<n;i++){
        int a,b;
        cin>>a>>b;
        for(j=0;j<b;j++){
            int to,cost;
            cin>>to>>cost;
            v[i].emplace_back(to,cost);
        }
    }
    priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> q;
    q.push(make_pair(0,0));
    dist[0]=0;
    while(!q.empty()){
        pair<int,int> e;
        e=q.top();q.pop();
        if(used[e.second]) continue;
        used[e.second]=true;
        dist[e.second]=min(dist[e.second],e.first);
        for(auto p:v[e.second]){
            if(!used[p.first]){
                q.push(make_pair(dist[e.second]+p.second,p.first));
            }
        }
    }
    for(i=0;i<n;i++){
        cout<<i<<' '<<dist[i]<<endl;
    }
}