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()

	list := make([][]int, n)
	weight := make([]int, n)
	for i := range list {
		list[i] = make([]int, n)
		weight[i] = NIL
		for j := range list[i] {
			list[i][j] = NIL
		}
	}

	for i := 0; i < n; i++ {
		u := scanInt()
		k := scanInt()
		for j := 0; j < k; j++ {
			v := scanInt()
			w := scanInt()
			list[u][v] = w
		}
	}

	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 i, w := range list[node.id] {
			if w == NIL {
				continue
			}
			heap.Push(h, Node{id: i, weight: w + node.weight})
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		fmt.Fprint(w, i)
		fmt.Fprint(w, " ")
		fmt.Fprint(w, weight[i])
		fmt.Fprintln(w)
	}
	w.Flush()
}

C++: #include <bits/stdc++.h>

using namespace std;

int n;
typedef pair<int, int> P;
const int N = 110;
vector<P> G[N];
int dis[N];
bool vis[N];

void dijkstra() {
    memset(vis, false, sizeof(vis));
    for (int i = 0; i < n; i++) dis[i] = INT_MAX;
    priority_queue<P, vector<P>, greater<P>> heap;
    heap.push({0, 0});
    dis[0] = 0;

    while (!heap.empty()) {
        int u = heap.top().second, cost = heap.top().first;
        heap.pop();
        if (vis[u]) continue;
        vis[u] = true;
        for (int i = 0; i < G[u].size(); i++) {
            int v = G[u][i].second, len = G[u][i].first;
            if (!vis[v] && dis[u] + len < dis[v]) {
                dis[v] = dis[u] + len;
                heap.push({dis[v], v});
            }
        }
    }
}

int main() {
    cin >> n;
    for (int i = 0; i < n; i++) {
        int u, k;
        cin >> u >> k;
        int v, c;
        for (int j = 0; j < k; j++) {
            cin >> v >> c;
            G[u].push_back({c, v});
        }
    }

    dijkstra();

    for (int u = 0; u < n; u++) {
        cout << u << " " << dis[u] << endl;
    }

    return 0;
}

C++: #include <bits/stdc++.h>
#define int long long
#define rng(i, l, r) for (size_t i = (l); i < (r); ++i)
#define rep(i, n) rng(i, 0, n)
#define gnr(i, l, r) for (size_t i = (r)-1; i >= (l); i--)
#define per(i, b) gnr(i, 0, b)
#define ALL(obj) (obj).begin(), (obj).end()    //1,2,3,...
#define rALL(obj) (obj).rbegin(), (obj).rend() //...,3,2,1

using namespace std;

const int INF = 1e18;
struct edge
{
    int to, cost;
};
using Graph = vector<vector<edge>>;

static const int MAX = 10000;

static const int YET = 0;
static const int CHK = 1;
static const int END = 2;

int n;
Graph G;

void dijkstra()
{
    priority_queue<pair<int, int>> pq;
    int seen[MAX];
    int dist[MAX];

    memset(seen, YET, sizeof(seen));
    //memset(dist, INF, sizeof(dist));
    rep(i, MAX) dist[i] = INF;

    dist[0] = 0;
    seen[0] = CHK;
    pq.push(make_pair(0, 0));

    while (!pq.empty())
    {
        auto minDistV = pq.top();
        pq.pop();
        int u = minDistV.second;
        int uc = minDistV.first * (-1);
        seen[u] = END;

        if (dist[u] < uc)
            continue;

        for (auto ne : G[u])
        {
            int nv = ne.to;
            int nvc = ne.cost;

            if (seen[nv] == END)
                continue;
            if (dist[u] + nvc < dist[nv])
            {
                dist[nv] = dist[u] + nvc;
                pq.push(make_pair(dist[nv] * (-1), nv));
                seen[nv] = CHK;
            }
        }
    }

    for (int i = 0; i < n; i++)
    {
        cout << i << " " << ((dist[i] == INF) ? -1 : dist[i]) << endl;
    }
}

void solve()
{

    // remove the bottom 3 lines when you submit this code.
    std::ifstream in("./sample.txt");
    std::cin.rdbuf(in.rdbuf());

    cin.tie(0);
    ios::sync_with_stdio(false);

    cin >> n;
    G.resize(n);
    for (int i = 0; i < n; i++)
    {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++)
        {
            int vertex, cost;
            cin >> vertex >> cost;
            G[u].push_back((edge){vertex, cost});
        }
    }

    dijkstra();

    return;
}

signed main()
{
    solve();
    return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<climits>
using namespace std;
 
#define N 10000
int n;
 
int g[N][N];
 
int weight[N];
bool us[N];
 
//prim
void prim(){
 
  int v;
  
  weight[0]=0;
   
  while(true){
    v=-1;
    
    for(int i=0;i<n;i++){
      if(us[i]!=true && (v==-1 ||weight[i]<weight[v]))v=i;
    }
 
    if(v==-1)break;
    us[v]=true;
  
 
    for(int i=0;i<n;i++){
      if(weight[i]>(g[v][i]+weight[v])){
 
        weight[i]=(g[v][i]+weight[v]);
        //      cout <<"fsafa"<<endl;
      }
    }
  }
  
}
 
 
int main(){
 
  int u,k1,c,v;
 
  for(int i=0;i<N;i++){
    for(int j=0;j<N;j++){
      g[i][j]=9953535;
    }
  }
 
  //load n
  cin >>n;
 
  //load data
  for(int i=0;i<n;i++){
    weight[i]=INT_MAX;
    us[i]=false;
    scanf("%d %d",&u,&k1);
    for(int j=0;j<k1;j++){
      scanf("%d %d",&v,&c);
      g[u][v]=c;
      //    cout <<g[i][j]<<" ";
    }
    //    cout <<endl;
  }
 
 
 
 
  //print
  prim();
 
  for(int i=0;i<n;i++){
    cout <<i<<" "<<weight[i]<<endl;
  }
  return 0;
 
}

C++: #include <iostream>
using namespace std;

static const int MAX=100;
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;
static const int INF=(1<<21);

int n,M[MAX][MAX];

void dig(){
  int color[MAX],d[MAX];
  for(int i=0;i<n;i++){
    color[i]=WHITE;
    d[i]=INF;
  }


d[0]=0;
color[0]=GRAY;

int minc,u;
while(1){
  minc=INF;
  u=-1;
  for(int i=0;i<n;i++){
    if(color[i]!=BLACK&&minc>d[i]){
      minc=d[i];
      u=i;
    }
  }
if(u==-1) break;
  color[u]=BLACK;

  for(int v=0;v<n;v++){
    if(M[u][v]!=INF&&color[v]!=BLACK){
      if(d[v]>d[u]+M[u][v]){
        d[v]=d[u]+M[u][v];
        color[v]=GRAY;
      }
    }
  }
 }

 for(int i=0;i<n;i++){
   cout<<i<<" "<<(d[i]==INF?-1:d[i])<<endl;
 }
}
int main(){
  cin>>n;
  for(int i=0;i<n;i++){
    for(int j=0;j<n;j++){
      M[i][j]=INF;
    }
  }

  int u,k,v,c;
  for(int i=0;i<n;i++){
    cin>>u>>k;
    for(int j=0;j<k;j++){
      cin>>v>>c;
      M[u][v]=c;
    }
  }

  dig();
  return 0;
}

C++: #include<iostream>
using namespace std;
static const int INF=(1<<21);
int M[100][100];
void dij(int n, int d[], int color[]){
	d[0]=0;
	color[0]=1;
	int minv;
	while(1){
		minv=INF;
		int u=-1;
		for(int i=0; i<n; i++){
			if(minv>d[i] && color[i]!=2){
				u=i;
				minv=d[i];
			}
		}
		if(u==-1)
			break;
		color[u]=2;
		for(int v=0; v<n; v++){
			if(color[v] !=2 & M[u][v]!=INF){
				if(d[v]>d[u]+M[u][v]){
					d[v]=d[u]+M[u][v];
					color[v]=1;
				}
			}
		}
	}
}
int main(){
	int n;
	cin>>n;
	for(int i=0; i<n; i++){
		for(int j=0; j<n; j++){
			M[i][j]=INF;
		}
	}
	int k, c, u, v;
	for(int i=0; i<n; i++){
		cin>>u>>k;
		for(int j=0; j<k; j++){
			cin>>v>>c;
			M[u][v]=c;
		}
	}
	int d[n], color[n];
	for(int i=0; i<n; i++){
		d[i]=INF;
		color[i]=0;
	}
	dij(n, d, color);
	for(int i=0; i<n; i++){
		cout<<i<<" ";
		if(d[i]==INF)
			cout<<-1<<endl;
		else
			cout<<d[i]<<endl;
	}
	return 0;
}