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 <vector>
#include <iostream>
#include <algorithm>
#include <limits>

using namespace std;
using graph = vector<vector<int>>;


int main() {
    int n;
    cin >> n;

    graph G(n, vector<int>(n, -1));
    for (int i = 0; i < n; ++i) {
        int u, k;
        cin >> u >> k;

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

    // Dijkstra's algorithm
    vector<int> d(n, -1);
    vector<bool> visited(n, false);

    d[0] = 0;
    visited[0] = true;
    while (1) {
        int u = -1;
        int v = -1;
        int minw = numeric_limits<int>::max();
        for (int i = 0; i < n; ++i) {
            if (!visited[i])
                continue;
            for (int j = 0; j < n; ++j) {
                if (visited[j] || G[i][j] < 0)
                    continue;
                int w = G[i][j] + d[i];
                if (w < minw) {
                    u = i;
                    v = j;
                    minw = w;
                }
            }
        }
        if (v < 0) {
            break;
        }
        d[v] = minw;
        visited[v] = true;
    }

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

    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

int cost[100][100];
int d[100];//??????s?????????????°??????¢
bool used[100];
int arrow;//????????°

const int INF = 10000000;

void dijkstra(){
  fill(d,d+arrow,INF);
  fill(used,used + arrow,false);
  d[0] = 0;

  while(1){
    int v=-1;
    // ???????????????????????????????????????????????¢???????°???????????????¢???
    for(int u=0;u<arrow;u++){
      if(!used[u] && (v == -1 || d[u] < d[v])) v = u;
    }

    if(v == -1) break;

    used[v] = true;

    for(int u=0; u<arrow; u++){
      if(cost[v][u] != INF){
        d[u] = min(d[u],d[v] + cost[v][u]);
      }
    }
  }

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

}

int main(){

    cin >> arrow;

    int n,a,v,c;



    for(int i=0;i<arrow;i++){
      for(int j=0;j<arrow;j++){
        cost[i][j] = INF;
      }
    }

    /*for(int i=0; i<arrow; i++){
      cost[i][i] = 0;
    }*/

    for(int u=0;u<arrow;u++){

      cin >> n >> a;

      for(int i=0; i<a;i++){
        cin >> v >> c;
        cost[n][v] = c;
      }
    }

    dijkstra();

    return 0;
}

C++: #include <iostream>
#include <cmath>
#define INF 1000000000
using namespace std;

int main(){
	int n;
	int cost[100][100];
	cin >> n;
	for(int i = 0;i < n;i++){
		for(int j = 0;j < n;j++) cost[i][j] = INF;
		cost[i][i] = 0;
	}
	for(int i = 0;i < n;i++){
		int now,m;
		cin >> now >> m;
		for(int j = 0;j < m;j++){
			int a,b;
			cin >> a >> b;
			cost[i][a] = b;
		}
	}
	for(int k = 0;k < n;k++){
		for(int i = 0;i < n;i++){
			for(int j = 0;j < n;j++){
				cost[i][j] = min(cost[i][j],cost[i][k] + cost[k][j]);
			}
		}
	}
	
	for(int i = 0;i < n;i++) cout << i << " " << cost[0][i] << endl;
	return 0;
}

C++: #include<iostream>
#include<cstdio>
#define INF 1<<30
#define FinishFunction return 0
#define MAX 1000000
using namespace std;
  
  
struct edge {
  int from,to,cost,k;
};
  
edge es[MAX];
  
  
  
int main(){
  int n,u,k,E,c,v;
  E = 0;
  scanf("%d",&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);
      es[E].from = u;
      es[E].to = v;
      es[E++].cost = c;
    }
  }
  
    
  int d[MAX];
  for(int i=0;i<n;i++)d[i] = INF;
  d[0] = 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;
  
  
  }
  
  for(int i=0;i<n;i++)cout << i << " " << d[i] << endl;
  
  FinishFunction;
}

C++: #include <bits/stdc++.h>
using namespace std;

#define INF 1<<29
#define MAXV 100

int V;      //????????°
int cost[MAXV+10][MAXV+10];

vector<int> dijkstra(int s){
    vector<int> d(V,INF);
    bool used[MAXV+10];
    for(int i=0;i<MAXV+10;i++) used[i]=false;

    d[s]=0;
    while(true){
        //??????????????????????????????????????§s??????????????¢???????°?????????????v??¨??????
        int v=-1;
        for(int u=0;u<V;u++){
            if(!used[u] and (v==-1 or d[u]<d[v])) v=u;
        }

        if(v==-1) break;
        
        used[v]=true;
        for(int u=0;u<V;u++){
            d[u] = min(d[u],d[v]+cost[v][u]);
        }
    }
    return d;
}

int main(){
    // initialize
    for(int i=0;i<MAXV+10;i++) for(int j=0;j<MAXV+10;j++) cost[i][j]=INF;

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

    vector<int> dis = dijkstra(0);
    for(int i=0;i<dis.size();i++){
        printf("%d %d\n",i,dis[i]);
    }
}

C++: #include<iostream>
#include<algorithm>
#include<queue>
using namespace std;
static const int MAX = 10000;
static const int INFTY = (1<<20);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<pair<int,int> > adj[MAX];

void dijkstra(){
  priority_queue<pair<int,int> > PQ;
  int color[MAX];
  int d[MAX];
  for(int i=0;i<n;i++){
    d[i] = INFTY;
    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(color[v] == BLACK) continue;
      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] == INFTY ? -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;
}