Go: package main

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

const NIL = -1

type Node struct {
	id     int
	weight int
}

func init() {
	sc.Split(bufio.ScanWords)
}

type NodeHeap []Node

func (h NodeHeap) Len() int           { return len(h) }
func (h NodeHeap) Less(i, j int) bool { return h[i].weight < h[j].weight }
func (h NodeHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *NodeHeap) Push(x interface{}) {
	*h = append(*h, x.(Node))
}

func (h *NodeHeap) Pop() interface{} {
	old := *h
	n := len(old)
	x := old[n-1]
	*h = old[0 : n-1]
	return x
}

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func main() {
	n := scanInt()

	route := make([][]Node, n)
	weight := make([]int, n)
	for i := 0; i < n; i++ {
		weight[i] = NIL
	}

	for i := 0; i < n; i++ {
		u := scanInt()
		k := scanInt()
		route[i] = make([]Node, k)
		for j := 0; j < k; j++ {
			route[u][j] = Node{id: scanInt(), weight: scanInt()}
		}
	}

	start := Node{id: 0, weight: 0}
	h := &NodeHeap{start}
	heap.Init(h)

	for h.Len() > 0 {
		node := heap.Pop(h).(Node)
		if weight[node.id] != NIL {
			continue
		}
		weight[node.id] = node.weight

		for _, nextNode := range route[node.id] {
			if weight[nextNode.id] != NIL {
				continue
			}
			nextNode.weight += node.weight
			heap.Push(h, nextNode)
		}
	}

	for i, w := range weight {
		fmt.Println(i, w)
	}
}

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]=2001;
		}
	}
	REP(i, n) {
		cin>>u>>k;
		REP(i, k) {
			cin>>a>>b;
			m[u][a]=b;
			if(m[u][a]==-1) m[u][a]=2001;
		}
		color[i]=0;
		d[i]=2001;
	}
	a=0;
	d[0]=0;
	while(1){
		min=2001;
		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]!=2001){
				if(d[i]>m[u][i]+d[u]){
					d[i]=m[u][i]+d[u];
				}
			}
		}

	}
	min=0;
	REP(i,n){
		cout<<i<<" "<<(d[i] == 2001 ? -1 : d[i])<<endl;
	
	}
	return 0;
}

C++: #include "bits/stdc++.h"
using namespace std;
int main()
{
    int n, inf = 100000000;
    scanf("%d", &n);
    vector<vector<pair<int, int>>> a(n, vector<pair<int, int>>(0));
    for (int i = 0, u, k; i < n; i++)
    {
        scanf("%d %d", &u, &k);
        for (int j = 0, v, c; j < k; j++)
        {
            scanf("%d %d", &v, &c);
            a[i].push_back(make_pair(c, v));
        }
    }
    
    vector<int> cost(n, inf), vis(n, 0);
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>> > q;
    cost[0] = 0;
    q.push(make_pair(0, 0));
    for (pair<int, int> t; !q.empty(); )
    {
        
        t = q.top();
        q.pop();
        vis[t.second] = true;
        if (cost[t.second] < t.first)
        {
            continue;
        }
        for (int i = 0; i < a[t.second].size(); i++)
        {
            pair<int, int> j = a[t.second][i];
            if (!vis[j.second] && cost[j.second] > cost[t.second] + j.first)
            {
                cost[j.second] = cost[t.second] + j.first;
                q.push(make_pair(cost[j.second], j.second));
            }
        }
    }
    for (int i = 0; i < n; i++)
    {
        printf("%d %d\n", i, cost[i]);
    }
}

C++: #include<bits/stdc++.h>
using namespace std;
#define int long long
typedef pair<int,int> P;
vector<vector<P> > G;
signed main(){
  int n;
  cin>>n;
  int INF=1LL<<55LL;
  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(P(v,c));
    }
  }
  int d[n];
  for(int i=0;i<n;i++) d[i]=INF;
  d[0]=0;

  priority_queue<P,vector<P>,greater<P> > q;
  d[0]=0;
  q.push(P(0,0));

  while(!q.empty()){
    P p=q.top();q.pop();
    int u=p.second,c=p.first;
    //cout<<u<<" "<<c<<endl;
    if(d[u]<c) continue;
    for(P e:G[u]){
      int v=e.first,w=e.second;
      if(d[v]>d[u]+w){
	d[v]=d[u]+w;
	q.push(P(d[v],v));
	//cout<<v<<":"<<d[v]<<endl;
      }
    }
  }
  
  for(int i=0;i<n;i++) cout<<i<<" "<<d[i]<<endl;
  return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<queue>
#include<vector>
#include<utility>

#define INF 9999999999

using namespace std;

const int MAX_N = 100000;

int d[MAX_N];

struct edge{
	int to;   //?????????
	int cost; //?????????
};

typedef pair<int,int>P;

void dijkstra(int s,int n)
{
	int k,l,p,q,r,u,v,cost,m;
	vector<edge> edgelist[n];
	for(int i=0;i<n;i++){
		scanf("%d",&u);
		scanf("%d",&m);
		for(int j=0;j<m;j++){
			edge e;
			scanf("%d",&v);
			scanf("%d",&cost);
			e.to = v;	e.cost = cost;
			edgelist[i].push_back(e);
		}
	}
	priority_queue<P,vector<P>,greater<P> > que;
	d[s] = 0;
	que.push(P(0,s));
	while(!que.empty()){
		P p = que.top();
		que.pop();
		int v = p.second;
		if(d[v] < p.first) continue;
		vector<edge>::iterator it = edgelist[v].begin();
		while(it != edgelist[v].end()){
			if(d[it->to] > d[v] + it->cost){
				d[it->to] = d[v] + it->cost;
				que.push(P(d[it->to],it->to));
			}
			it++;
		}
	}
}

int main()
{
	int k,l,m,n,s;
	scanf("%d",&n); // ?????°?????\???
	fill(d,d+n,INF);
	dijkstra(0,n);
	for(int i=0;i<n;i++){
		printf("%d %d\n",i,d[i]);
	}
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <climits>
#include <string>
#include <vector>
#include <utility>
#include <functional>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <cassert>

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

const ll MOD = ll(1e9) + 7;
const ll INF = LLONG_MAX;
const ll MAX_N = ll(1e5) + 5;
const double EPS = 10e-8;
const double PI = 3.14159265359;

#define REP(i, n) for (ll i = 0; i < n; i++)
#define REPR(i, n) for (ll i = n; i >= 0; i--)
#define FOR(i, m, n) for (ll i = m; i < n; i++)

int dx[] = {1, 0, -1, 0}, dy[] = {0, 1, 0, -1};

struct UF {
    static const int MAX_N = 100000;
    int p[MAX_N];
    int r[MAX_N];

    void init(int n) {
        REP(i, n) {
            p[i] = i;
            r[i] = 0;
        }
    }
    int find(int x) {
        if (p[x] == x) return x;
        return p[x] = find(p[x]);
    }
    void unite(int x, int y) {
        x = find(x);
        y = find(y);
        if (x == y) return;
        if (r[x] < r[y]) swap(x, y);
        if (r[x] == r[y]) r[x]++;
        p[y] = x;
    }
    bool same(int x, int y) { return find(x) == find(y); }
};

int n, d[100000];
vector<P> g[100000];

void dijkstra(int s) {
    fill(d, d + n, 99999999*2);
    d[s] = 0;
    priority_queue<P> que;
    que.push({0, s});
    while (!que.empty()) {
        P p = que.top();
        que.pop();
        int u = p.second;
        if (p.first > d[u]) continue;
        REP(i, g[u].size()) {
            int v = g[u][i].first, cost = g[u][i].second;
            if (d[v] > d[u] + cost) {
                d[v] = d[u] + cost;
                que.push({d[v], v});
            }
        }
    }
}

int main() {
    cin >> n;
    REP(i, n) {
        int from, k;
        cin >> from >> k;
        REP(j, k) {
            int to, c;
            cin >> to >> c;
            g[from].push_back({to, c});
        }
    }
    dijkstra(0);
    REP(i, n) { cout << i << " " << d[i] << endl; }
    return 0;
}