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<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; // スタート位置はノード0
    color[0] = GRAY;

    while(1){
        minv = INFTY;
        int u = -1;
        for(int i=0;i<n;i++){
            if(color[i] != BLACK && d[i] < minv){
                u = i;
                minv = d[i];
            }
        }
        if(u == -1)break; //例外処理
        color[u] = BLACK;

        for(int v =0;v<n;v++){
            if(M[u][v] != INFTY && color[v] != BLACK){
                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 <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

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];

int prim() {
   int u, minv;
   int d[MAX], p[MAX], color[MAX];

   // 初期化
   rep(i, n) {
      d[i] = INFTY;
      p[i] = -1;
      color[i] = WHITE;
   }

   d[0] = 0;

   while(1) {
      minv = INFTY;
      u = -1;

      rep(i, n){
         if (minv > d[i] && color[i] != BLACK) {
            u = i;
            minv = d[i];
         }
      }
      if(u == -1) break;
      // uの決定
      color[u] = BLACK;

      rep(v, n) {
         if(color[v] != BLACK && M[u][v] != INFTY) {
            if(d[v] > M[u][v]) {
               d[v] = M[u][v];
               p[v] = u;
               color[v] = GRAY;
            }
         }
      }
   }
   int sum = 0;
   rep(i, n) {
      if(p[i] != -1) sum += M[i][p[i]];
   }
   return sum;
}

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

   // 初期化
   rep(i, n) {
      d[i] = INFTY;
      color[i] = WHITE;
   }

   d[0] = 0;
   color[0] = GRAY;

   while(true) {
      minv = INFTY;
      int u = -1;
      rep(i, n) {
         if(minv > d[i] && color[i] != BLACK) {
            u = i;
            minv = d[i];
         }
      }
      if (u == -1) break;

      // 最も小さいコストのuが決まる 初回は必ず0になる
      color[u] = BLACK;

      rep(v, n) {
         // 0 ~ n-1の頂点が未訪問かつuとの経路がある場合
         if(color[v] != BLACK && M[u][v] != INFTY) {
            // 頂点uを通った方が目的地に近い場合
            if (d[v] > d[u] + M[u][v]) {
               d[v] = d[u] + M[u][v];
               color[v] = GRAY;
            }
         }
      }
   }

   rep(i, n) {
      cout << i << " " << (d[i] == INFTY ? -1 : d[i]) << endl;
   }
}

int main(){
   cin >> n;
   rep(i, n) {
      rep(j, n) {
         M[i][j] = INFTY;
      }
   }

   int k, c, u, v;
   rep(i, n) {
      cin >> u >> k;
      rep(j, k){
         cin >> v >> c;
         M[u][v] = c;
      }
   }

   dijkstra();

   return 0;
}

C++: #include <cstdio>
#include <iostream>
#include <cmath>
#include <ctype.h>
#include <string>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <map>
#include <queue>
#include <utility>
#include <vector>
#include <set>
#include <list>
#include <cstring>
#include <stack>

using namespace std;

#define mod 1000000007

int main()
{
	int n;
	int graph[101][101] = {};
	cin >> n;
	int ans[101] = {};
	for(int i = 0; i < n; i++){
		ans[i] = -1;
		int u, k;
		cin >> u >> k;
		for(int j = 0; j < k; j++){
			int v, c;
			cin >> v >> c;
			graph[u][v] = c;
		}
	}
	priority_queue<pair<int, int> > qu;
	qu.push(make_pair(0, 0));
	ans[0] = 0;
	while(!qu.empty()){
		int nowd = -(qu.top()).first;
		int nownode = (qu.top()).second;
		qu.pop();
		for(int i = 0; i < n; i++){
			if(graph[nownode][i] == 0) continue;
			int next = nowd + graph[nownode][i];
			if(ans[i] == -1 || ans[i] > next){
				ans[i] = next;
				qu.push(make_pair(-next, i));
			}
		}
	}
	for(int i = 0; i < n; i++){
		cout << i << " " << ans[i] << endl;
	}
}

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;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n)   FOR(i,0,n)
#define pb emplace_back
typedef long long ll;
typedef pair<int,int> pint;

vector<pint> vp[500001];
int d[100001];
int INF=1000100010;
int n;
int dijkstra(int st){
    priority_queue<pint,vector<pint>,greater<pint> > pq;
    rep(i,n) d[i]=INF;
    d[st]=0;
    pq.push(make_pair(0,st));
    while(!pq.empty()){
        pint pi=pq.top();pq.pop();
        int t=pi.second;
        if(d[t]<pi.first) continue;
        for(auto it:vp[t]){
            if(d[it.second]>d[t]+it.first){
                d[it.second]=d[t]+it.first;
                pq.push(make_pair(d[it.second],it.second));
            }
        }
    }
}
int main(){
    cin>>n;
    int u,k,v,c;
    rep(i,n){
        cin>>u>>k;
        rep(j,k){
            cin>>v>>c;
            vp[u].pb(c,v);
        }
    }
    dijkstra(0);
    rep(i,n){
        cout<<i<<" "<<d[i]<<endl;
    }
    return 0;
}