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;

const int INF = LONG_LONG_MAX;
typedef pair<int, int> P;
#define int long long

struct edge {int to, cost;};

/*
[input]
const vector<vector<edge>> &graph : ??\?????°??????
int s : ?§????
int g : ??????
n*/
int dijkstra(const vector<vector<edge>> &graph, int s, int g ) {
  // ????????????????±?????????????????????????
  vector<int> d(graph.size(), INF);
  // ????§?????????????????????????0????????????
  d[s] = 0;
  // ??????????????????now
  set<P> now;
  // ????§?????????????now????????\
  now.insert(P(0, s));
  
  // now????????????????????§
  while(!now.empty()) {
    // ?????¨?????????????????????pos???????´?
    int pos = now.begin()->second;
    // ?????¨??????????????????????????????????±???????????????????????????????
    if (pos == g) {
      for(int i = 0; i <= g; i++) {
        cout << i << " " << d[i] << endl;
      }
      return INF;
    }
    // now????????¢?´¢?????????????¶????
    now.erase(now.begin());
    // ?????¨??????????????¨???????????¢?´¢
    for(auto ed: graph[pos]) {
      // ??\?¶??????????????????????????????????????????¨??????????????§????????????
      // ??¨??\?¶?????????§?????¨????????????????????????????????§???????????°
      if(d[ed.to] > d[pos] + ed.cost) {
        // now????????\?¶?????????????????±????????????????????????????
        now.erase(P(d[ed.to], ed.to));
        d[ed.to] = d[pos] + ed.cost;
        now.insert(P(d[ed.to], ed.to));
      }
    }
  }
  return INF;
}
  
signed main() {
  int num;
  cin >> num;
  vector<vector<edge>> graph(num, vector<edge>());
  int f, n, k, v, c;
  for(int i = 0; i < num; i++) {
    cin >> f >> k;
	if(k == 0) continue;
    for(int j = 0; j < k; j++) {
      cin >> v >> c;
      graph[f].push_back(edge{v, c});
      graph[v].push_back(edge{f, c});
    }
  }
  dijkstra(graph, 0, num - 1);
  return 0;
}

C++: #include <utility>
#include <vector>
#include <queue>
#include <functional>
#include <cassert>

using namespace std;

class Dijkstra {
#define MAX_V 101
  typedef pair<int, int> P;

private:
  const int INF = 1e9 + 10;
  struct Edge {
    int to, cost;
    Edge(int to, int cost): to(to), cost(cost) { }
  };

  int V;
  vector<Edge> G[MAX_V];

public:

  Dijkstra(int V): V(V) { 
    if (V >= MAX_V) {
      assert(false);
    }
  }

  void AddEdge(int from, int to, int cost) {
    G[from].push_back(Edge(to, cost));
  }

  vector<int> Solve(int s) {
    priority_queue<P, vector<P>, greater<P>> que;
    vector<int> d(V, INF);
    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;
      }
      for (int i = 0; i < G[v].size(); i++) {
        Edge e = G[v][i];
        if (d[e.to] > d[v] + e.cost) {
          d[e.to] = d[v] + e.cost;
          que.push(P(d[e.to], e.to));
        }
      }
    }

    return d;
  }
};

#include <iostream>


int main() {
  int n;
  cin >> n;
  Dijkstra dijkstra(n);
  for (int i = 0; i < n; i++) {
    int u, k;
    cin >> u >> k;
    for (int j = 0; j < k; j++) {
      int t, c;
      cin >> t >> c;
      dijkstra.AddEdge(u, t, c);
    }
  }

  vector<int> d = dijkstra.Solve(0);

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

  return 0;
}

C++: #include <iostream>
using namespace std;
static const int MAX = 100;
static const int INFTY = (1<<21);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n,M[MAX][MAX];

void dijkstra(){
  int minv;
  int d[MAX], color[MAX];

  for(int i=0; i<n; i++){
    d[i] = INFTY;
    color[i] = WHITE;
  }

  d[0] = 0;
  color[0] = GRAY;
  while(1){
    minv = INFTY;
    int u = -1;
    for(int i=0; i<n; i++){
      if(minv > d[i] && color[i] != BLACK){
        u = i;
        minv = d[i];
      }
    }
    if(u == -1) break;
    color[u] = BLACK;
    for(int v=0; v<n; v++){
      if(color[v] != BLACK && M[u][v] != INFTY){
        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] == INFTY ? -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] = INFTY;
    }
  }

  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;
    }
  }

  dijkstra();

  return 0;
}

C++: #include<stdio.h>
#include<algorithm>
#include<iostream>
using namespace std;
#define INF 1000000000
int main()
{
	long long int min,n,u,k,v,c,dist[100][100],s,cost[100],t[100],l=1;
	cin>>n;
	for(int i=0;i<n;i++)
	{
		for(int j=0;j<n;j++)
		{
			dist[i][j]=INF;
			cost[i]=INF;
			t[i]=-1;
		}
	}
	min=INF;
	dist[0][0]=0;
	for(int i=1;i<=5;i++)
	{
		cin>>u;
		cin>>k;
		for(int i=1;i<=k;i++)
		{
			cin>>v>>c;
			dist[u][v]=c;
		}
	}
	s=0;
	cost[s]=0;
	while(l!=n)
	{
		for(int i=0;i<n;i++)
		{
			if(dist[s][i]!=INF)
			{
				if(cost[s]+dist[s][i]<cost[i])
				{
					cost[i]=cost[s]+dist[s][i];
				}
				
			}
		}
		t[s]=1;
		for(int i=1;i<n;i++)
		{
			if(cost[i]<min&&t[i]==-1)
			{
				min=cost[i];
				s=i;
			}
		}
		min=INF+1;
		l++;
	}
	for(int i=0;i<n;i++)
	{
		cout<<i<<" "<<cost[i]<<endl;
	}
	return 0;
}