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++: #define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <iostream>
#include <list>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <queue>
#include <iomanip>
#define INF 1050000000
 
using namespace std;

#define MAX_V 101

int d[MAX_V][MAX_V];  // d[u][v]は辺e=(u,v)のコスト(存在しない場合はINF、ただしd[i][i]=0とする)
int V;                // 頂点数
void warshall_floyd(int n) {
	V = n;

	for (int i = 0; i < V; i++)
		for (int j = 0; j < V; j++) 
			for (int k = 0; k < V; k++)
				d[0][j] = min(d[0][j], d[0][k] + d[k][j]);
}

int main(void)
{
	int n, u, v, k, c;

	cin >> n;

	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (i == j) d[i][j] = 0; 
			else d[i][j] = INF;
		}
	}

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

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


	return (0);
}

C++: #include <iostream>
#include <cstdio>
#include <string>
#include <list>
#include <stack>
#include <queue>
#include <algorithm>
#include <utility>
#include <vector>
#include <map>
#include <bitset>

using namespace std;

int main()
{
	int N;
	cin>>N;
	bitset<100> data(1);
	
	vector<vector<int> > cost(N,vector<int>(N,100001));
	cost[0][0]=0;
	pair<int,int> ddata;
	for(int i=0;i<N;i++){
		int u,k;
		cin>>u>>k;
		for(int j=0;j<k;j++){
			cin>>ddata.first>>ddata.second;
			cost[u][ddata.first]=ddata.second;
		}
	}
	//
	int n;
	for(int i=0;data.count()<N;i=n){
		n=1;
		for(int j=1;j<N;j++){
			if(i!=j&&cost[0][j]>cost[0][i]+cost[i][j]){
				cost[0][j]=cost[0][i]+cost[i][j];
			}
			if((!data[j]&&cost[i][j]<cost[i][n])||i==n){
				n=j;
			}
		}
		data.set(n);
	}
	for(int i=0;i<N;i++){
		cout<<i<<' '<<cost[0][i]<<endl;
	}
	return 0;
}

C++: #include<iostream>
#include<vector>
#include<algorithm>
#define MAX_V 100
#define INF 1e9
using namespace std;
int cost[MAX_V][MAX_V];
int d[MAX_V];
bool used[MAX_V];
int V;
void dijkstra(int s) {
	for (int i = 0; i < V; i++) {
		d[i] = INF;
		used[i] = false;
	}
	d[s] = 0;
	while (true) {
		int v = -1;
		for (int u = 0; u < V; u++) {
			if (!used[u] && ((v == -1) || d[u] < d[v])) {
				v = u;
			}
		}
		//全ての頂点が到達済み
		if (v == -1) {
			break;
		}
		//集合に新たに頂点を追加
		used[v] = true;
		for (int u = 0; u < V; u++) {
			d[u] = min(d[u], d[v] + cost[v][u]);
		}
	}
}

int main() {
	for (int i = 0; i < V+90; i++) {
		for (int j = 0; j < V+90; j++) {
			cost[i][j] = INF;//iからjへの辺の重さ
		}
	}
	cin >> V;
	for (int i = 0; i < V; i++) {
		int u;
		cin >> u;
		int k;
		cin >> k;
		for (int j = 0; j < k; j++) {
			int v;
			cin >> v;
			int c;
			cin >> c;
			cost[u][v] = c;
		}
	}
	dijkstra(0);

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

C++: #include<iostream>
#include<cstdio>
#include<cstring>
#define INF 2000 
using namespace std;
int n;
int A[1000][1000];
int d[1000];
bool used[1000];
int D[1000][1000];
 
void Init(int f){
  for(int i=0;i<f;i++){
    for(int j=0;j<f;j++)D[i][j] = INF;
  }
 
}
 
int main(){
  scanf("%d",&n);
  int u,k,C,V;
  Init(n);
  
  for(int i=0;i<n;i++){
      scanf("%d %d",&u,&k);    
      for(int j=0;j<k;j++){
    scanf("%d %d",&V,&C);
    D[u][V] = C;
    D[V][u] = C;
      }    
  }
   
  for(int i=0;i<n;i++)D[i][i] = 0;
  for(int k=0;k<n;k++)for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j] = min(D[i][j],D[i][k] + D[k][j]);
  for(int i=0;i<n;i++){
    printf("%d %d\n",i,D[0][i]);
  }
 
  return 0;
}

C++: #include <iostream>
using namespace std;
#define MAX 100
#define INFTY 10000001
#define WHITE 0
#define GRAY 1
#define BLACK 2
#define DEFLT 0 // 初期値

int M[MAX][MAX], d[MAX];

void dijkstra(int n){
  int mincost, u, color[n], p[n];
  for(int i=0; i<n; i++){
    color[i] = WHITE;
    d[i] = INFTY;
  }

  d[DEFLT] = 0;
  p[DEFLT] = -1;

  while(true){
    mincost = INFTY;
    for(int i=0; i<n; i++){
      if(color[i] != BLACK && d[i] < mincost){
        mincost = d[i];
        u = i;
      }
    }

    if(mincost == INFTY) break;

    color[u] = BLACK;

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

int main(void){
  int n, u, k, v, c;
  cin >> n;

  for(u=0; u<MAX; u++){
    for(v=0; v<MAX; v++){
      M[u][v] = INFTY;
    }
  }

  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(n);

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

C++: #include<bits/stdc++.h>
#include<string>
#include<cctype>
#include<cmath>
#include<queue>
#include<stack> 
#define rep(i,n) for(int i=0;i<(n);i++)
using namespace std;
const int MAX_V=105;
int INF = 1000000000;
struct edge{int to,cost;};
typedef pair <int,int> P;

int V;
vector <edge> G[MAX_V];
int d[MAX_V];

void dijkstra(int s){
  priority_queue<P,vector<P>,greater<P> > que;
  fill(d,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));
      }
    }
  }
} 
  
int main(){
  int n;
  cin >> n; V=n;
  rep(i,n){
    int u,k;
    cin >> u >> k;
    rep(j,k){
      int to,cost;
      cin >> to >> cost;
      G[u].push_back(edge{to,cost});
    }
  }     

  dijkstra(0);
  rep(i,n){
    cout << i << ' ' << d[i] << endl;
  }
  return 0;
}