Go: package main

import (
	"strconv"
	"fmt"
	"bufio"
	"os"
)
const INF = 1 << 21
var scanner = bufio.NewScanner(os.Stdin)

func nextInt() int {
	scanner.Scan()
	i, e := strconv.Atoi(scanner.Text())
	if e != nil {
		panic(e)
	}
	return i
}


func main() {
	scanner.Split(bufio.ScanWords)
	n := nextInt()
	adj := make([][]int, n)
	for i := range adj {
		adj[i] = make([]int, n)
	}

	for i := 0;i < n; i++ {
		u := nextInt()
		k := nextInt()
		for j := 0; j < k; j++ {
			v := nextInt()
			c := nextInt()
			adj[u][v] = c
		}
	}

	// for i := range adj {
	// 	fmt.Println(adj[i])
	// }

	dist := make([]int, n)
	prev := make([]int, n)
	visited := make([]bool, n)
	dijkstra := func(start int, size int) {
		for i := 0; i < size; i++ {
			dist[i] = INF
			prev[i] = -1
			visited[i] = false
		}
		dist[start] = 0
		for {
			u := -1
			tmp_min := INF
			for i := 0; i < size; i++ {
				if visited[i] == false && dist[i] < tmp_min {
					tmp_min = dist[i]
					u = i
				}
			}
			if u == -1 {
				break
			}
			visited[u] = true
			for i := 0; i < size; i++ {
				if adj[u][i] > 0 {
					w := adj[u][i]
					newlen := dist[u] + w
					if newlen < dist[i] {
						dist[i] = newlen
						prev[i] = u
					}
				}
			}
		}
	}
	dijkstra(0, n)
	for i, cost := range dist {
		fmt.Printf("%d %d\n", i, cost)
	}
}

C++: #include <stdio.h>

using namespace std;


int main(){
	int n,count,t,min,min_index,tmp,left_node,right_node,dist;
	scanf("%d",&n);
	int distance[n][n],P[n];

	for(int i=0;i<n;i++){
		for(int k=0;k<n;k++)distance[i][k]=100001;
		P[i]=0;
	}
	distance[0][0] = 0;
	P[0]=1;

	for(int i=0;i<n;i++){
		scanf("%d %d",&left_node,&tmp);
		for(int k=0;k<tmp;k++){
			scanf("%d %d",&right_node,&dist);
			distance[left_node][right_node] = dist;
		}
	}

	while(count<n-1){

		min=100001;
		for(int i=1;i<n;i++){
			if(P[i]==0&&distance[0][i]<min){
				min_index = i;
				min = distance[0][i];
			}
		}
		t = min_index;
		P[t]=1;
		count++;

		for(int i=0;i<n;i++){
			if(distance[0][i] > distance[0][t]+distance[t][i]){
				distance[0][i]=distance[0][t]+distance[t][i];
			}
		}
	}

	for(int i=0;i<n;i++){
		printf("%d %d\n",i,distance[0][i]);
	}

    return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<queue>
using namespace std;
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;
static const int INF=(1<<21);
int n;
vector< pair<int,int> >adj[101];

void dijkstra(){
  priority_queue<pair<int,int> >pq;
  int color[101];
  int d[101];
  for(int i=0;i<n;++i){
    d[i]=INF;
    color[i]=WHITE;
  }
  d[0]=0;
  pq.push(make_pair(0,0));
  color[0]=GRAY;
  while(!pq.empty()){
    pair<int,int>f=pq.top();
    pq.pop();
    int u=f.second;
    color[u]=BLACK;
    if(d[u]<f.first*(-1)) continue;
    
    for(int j=0;j<adj[u].size();++j){
      int v=adj[u][j].first;
      if(d[v]>d[u]+adj[u][j].second){
	d[v]=d[u]+adj[u][j].second;
	pq.push(make_pair(d[v]*(-1),v));
	color[v]=GRAY;
      }
    }
  }
  for(int i=0;i<n;++i){
    cout<<i<<" "<<(d[i]==INF? -1 : d[i] )<<endl;
  }
}
int main(){
  int k,u,v,c;
  cin>>n;
  for(int i=0;i<n;++i){
    cin>>u>>k;
    for(int j=0;j<k;++j){
      cin>>v>>c;
      adj[u].push_back(make_pair(v,c));
    }
  }
  dijkstra();
  return 0;
}

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

const int Max = 105;
const int INF = (1<<29);
int n, G[Max][Max], Min, color[Max], d[Max], p[Max];
int u, k, v, c;

void dijstra()
{
    memset(color, -1, sizeof(color));
    for(int i=0; i<n; i++)
    {
        d[i] = INF;
    }
    d[0] = 0;
    p[0] = -1;
    while(1)
    {
        int minv = INF, u;
        for(int i=0; i<n; i++)
        {
            if(color[i]!=0 && d[i]<minv)
            {
                minv = d[i];
                u = i;
            }
        }
        if(minv==INF) break;
        color[u] = 0;

        for(int j=0; j<n; j++)
        {
            if(color[j]!=0 && G[u][j]!=INF && d[u]+G[u][j]<d[j])
            {
                d[j] = G[u][j]+d[u];
                p[j] = u;//j的父节点为u，有利于重建MST
            }
        }
    }
    //打印输出
    for(int i=0; i<n; i++)
    {
        cout << i << " " << d[i] << endl;
    }
}

int main()
{
    cin >> n;
    Min = 0;
    for(int i=0; i<n; i++)
    {
        for(int j=0; j<n; j++)
        {
            G[i][j] = INF;
        }
    }
    for(int i=0; i<n; i++)
    {
         cin >> u >> k;
         for(int i=0; i<k; i++)
         {
             cin >> v >> c;
             G[u][v] = c;//化为邻接矩阵
         }
    }
    dijstra();
    return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<cstring>
#include<climits>
#define INF INT_MAX
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;
  }

}

void djkstra(){
  for(int i=0;i<n;i++){
    d[i] = INF;
    used[i] = false;
  }
  d[0] = 0;

  while(true){
    int v = -1;
    for(int i=0;i<n;i++){
      if(!used[i] && (v == -1 || d[v] > d[i]))v = i;
    }
    if(v == -1)break;
    used[v] = true;
    for(int i=0;i<n;i++){
      d[i] = min(d[i],d[v] + D[v][i]);
    }
  }
}



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]);

  djkstra();
 
  for(int i=0;i<n;i++){
    printf("%d %d\n",i,d[i]);
  }

  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define REP(i,n) for(int i=0; i<(n); i++)
#define ALL(n) begin(n),end(n)
const int INF=1000000000;

using Graph=vector<vector<int>>;

int n;
vector<int> d;

void Dijkstra(const Graph &G){
    // 暫定の最短距離，頂点番号
    priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> que;
    que.emplace(d[0],0);

    // 距離を確定すべき頂点がなくなるまで続ける
    while(!que.empty()){
        pair<int,int> p=que.top();
        que.pop();
        int v=p.second;
        
        // 最短距離より大きい場合は無視
        if(d[v]<p.first) continue;

        REP(i,n){
            // 辺(v,i)がなければ無視
            if(G[v][i]==INF) continue;

            // 辺(v,i)を採用して距離が短くなるならば，暫定的に採用
            if(d[i]>d[v]+G[v][i]){
                d[i]=d[v]+G[v][i];
                que.emplace(d[i],i);
            }
        }
    }
}

int main(){
    cin>>n;

    // グラフの受け取り
    Graph G(n,vector<int>(n));
    REP(i,n){
        int u,k;
        cin>>u>>k;
        G[u].assign(n,INF);
        REP(j,k){
            int v,c;
            cin>>v>>c;
            G[u][v]=c;
        }
    }

    // d[i]=(無限大) で初期化
    d.assign(n,INF);
    d[0]=0;

    Dijkstra(G);

    REP(i,n){
        cout<<i<<" "<<d[i]<<endl;
    }
}