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<iostream>
#include<queue>
#define INF 100000000
using namespace std;
int main(){
  int n;cin>>n;
  int u,k,v,c;
  int mp[101][101],d[101];
  for(int i=0;i<=100;i++){
    d[i]=INF;
    for(int j=0;j<=100;j++)mp[i][j]=INF;
  }
    while(u!=n-1){
    cin>>u>>k;
    for(int i=0;i<k;i++){
      cin>>v>>c;
      if(mp[u][v]>c)mp[u][v]=c;
    }
  }
    d[0]=0;
    queue<int>p;
    p.push(0);
    int mn,s=0,cnt=n-1;
    while(cnt&&!p.empty()){
      s=p.back();
      mn=INF;
      for(int i=0;i<n;i++){
	if(d[i]>=d[s]+mp[s][i]){
	  d[i]=d[s]+mp[s][i];
	  if(mn>d[i])mn=d[i],k=i;
	}
      }
      if(mn!=INF)cnt--,p.push(k);
      else p.pop();
    }
    for(int i=0;i<n;i++)cout<<i<<" "<<d[i]<<endl;
    
  return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<algorithm>

#define MAX 100
static const int INFTY =(1<<21);

int n,M[MAX][MAX];
int unvisited=0,decide=1,comp_decide=2;

void dijkstra(){
	int d[MAX];
	int state[MAX];
	for(int i=0;i<n;i++){
		d[i]=INFTY;
		state[i]=unvisited;
	}
	d[0]=0;
	state[0]=0;
	while(1){
		int mincost=INFTY,u=-1;
		for(int i=0;i<n;i++){
			if(d[i]<mincost&&state[i]!=comp_decide){
				u=i;
				mincost=d[i];
			}
		}
		if(u==-1) break;
		state[u]=comp_decide;
		for(int v=0;v<n;v++){
			if(state[v]!=comp_decide&&M[u][v]!=INFTY){
				if(d[v]>d[u]+M[u][v]){
					d[v]=d[u]+M[u][v];
					state[v]=decide;
				}
			}
		}
	}
	for(int i=0;i<n;i++){
			printf("%d %d\n",i,(d[i]==INFTY ? -1:d[i]));
	}
}

int main(){
	scanf("%d",&n);
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			M[i][j]=INFTY;
		}
	}
	int u,k,v,c;
	for(int i=0;i<n;i++){
		scanf("%d %d",&u,&k);
		for(int j=0;j<k;j++){
			scanf("%d %d",&v,&c);
			M[u][v]=c;
		}
	}
	dijkstra();
}

C++: #include<iostream>
using namespace std;
#define MAX 100
#define INF (1<<21)
#define WHITE 0
#define GRAY 1
#define 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] = INF;
    color[i] = WHITE;
  }

  d[0] = 0;
  color[0] = GRAY;
  while(1){
    minv = INF;
    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] != INF){
	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 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 <bits/stdc++.h>
#define MAX_E 1000000
#define MAX_V 100000
#define INF 1e9
typedef long long ll;
using namespace std;
/*??????????????????????????? O(V*E)*/

//??????from????????????to???????????????cost??????
struct edge{int from, to, cost;};
edge es[MAX_E]; //???
ll d[MAX_V];   //???????????¢
int V,E;        //V???????????°???E????????°

//s???????????????????????????????????????????????¢????±???????.
void Bellman_Ford(int s){
  for(int i=0; i<V ;i++) d[i]=INF;
  d[s]=0;
  while(true){
    bool update=false;
    for(int i=0; i<E ;i++){
      edge e = es[i];
      if(d[e.from] != INF && d[e.to]> d[e.from] + e.cost){
	d[e.to] = d[e.from] + e.cost;
	update = true;
      }
    }
    if(!update) break;
  }
}

//true??????????????????????????¨??????
bool find_negative_loop(){
  memset(d,0,sizeof(d));

  for(int i=0; i<V ;i++){
    for(int j=0; j<E ;j++){
      edge e = es[j];
      if(d[e.to] > d[e.from] + e.cost){
	d[e.to] = d[e.from] + e.cost;
	
	//n??????????????´??°???????????????????????????????????¨?????????
	if(i == V-1) return true;
      }
    }
  }
  return false;
}

int main(){
  cin>>V;
  for(int i=0;i<V;i++){
    int u,k;
    cin>>u>>k;
    for(int j=0,v,c;j<k;j++){
      cin>>v>>c;
      es[E++]=(edge){u,v,c};
    }
  }

  for(int i=0;i<V;i++){
      Bellman_Ford(i);
    cout<<i<<' '<<d[0]<<endl;
}
}