Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)

	g := makeGraph(n)
	for i := 0; i < n; i++ {
		u := getNextInt(scanner)
		k := getNextInt(scanner)
		for ii := 0; ii < k; ii++ {
			v := getNextInt(scanner)
			c := getNextInt(scanner)
			g[u][v] = c
		}
	}

	ans := make([]int, n)
	im := make(IntMap, 1)
	im.increment(0)
	for len(im) < n {
		min := 1 << 30
		x := -1
		for u := range im {
			for v := 0; v < n; v++ {
				if im.get(v) != 0 {
					continue
				}
				if min > ans[u]+g[u][v] {
					min = ans[u] + g[u][v]
					x = v
				}
			}
		}
		im.increment(x)
		ans[x] = min
	}

	for i := 0; i < n; i++ {
		fmt.Fprintln(writer, fmt.Sprintf("%d %d", i, ans[i]))
	}
	writer.Flush()
}

func makeGraph(n int) [][]int {
	g := make([][]int, n)
	for i := 0; i < n; i++ {
		g[i] = make([]int, n)
		for ii := 0; ii < n; ii++ {
			g[i][ii] = 1 << 30
		}
	}

	return g
}

// IntMap ...
type IntMap map[int]int

func (m IntMap) get(key int) int {
	if _, ok := m[key]; ok {
		return m[key]
	}
	return 0
}
func (m IntMap) increment(key int) {
	if _, ok := m[key]; ok == false {
		m[key] = 0
	}
	m[key]++
}

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;
    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 Lens 101
#define Inf 1<<22

using namespace std;
int N;
int w[Lens][Lens],p[Lens],d[Lens];
char c[Lens];

void dijkstra()
{
	d[0] = 0;
	while (true)
	{
		int u = -1;
		int minv = Inf;
		for (int i = 0; i < N; i++)
		{
			if (c[i] == 'w'&&minv > d[i])
			{
				minv = d[i];
				u = i;
			}
		}
		if (u == -1) break;
		c[u] = 'b';
		for (int v = 0; v < N; v++)
		{
			if (c[v] == 'w'&&w[u][v] != Inf)
				d[v] = min(d[v], w[u][v]+d[u]);
		}
	}
}

int main()
{
	cin >> N;
	for (int i = 0; i < N; i++)
	{
		c[i] = 'w';
		d[i] = Inf;
		p[i] = -1;
		int u,n;
		cin >> u >> n;
		for (int j = 0; j < n; j++)
		{
			int v, tw;
			cin >> v >> tw;
			w[u][v] = tw;
		}
	}
	for(int i=0;i<N;i++)
		for (int j = 0; j < N; j++)
		{
			if (w[i][j] == 0)
				w[i][j] = Inf;
		}
	dijkstra();
	for (int i = 0; i < N; i++)
		cout << i <<' '<< d[i] << endl;
	return 0;
}

C++: //
//  ALDS_12_B.cpp
//  
//
//  Created by 杵鞭俊 on 2018/07/24.
//

#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;
    color[0]=GRAY;
    while (1) {
        minv=INFTY;
        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]!=INFTY){
                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++: #define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <stdio.h>
#include <cstring>
#define maxn 101
#define INF 0x3f3f3f3f
using namespace std;

int m[maxn][maxn] = {}, d[maxn] = {}, color[maxn] = {};
int n;

void Dijkstra()
{
	for (int i = 1; i < n; i++)
		d[i] = INF;
	d[0] = 0;
	while (true)
	{
		int mincost = INF,u;
		for(int i=0;i<n;i++)
			if (d[i] < mincost&&color[i]==0)
			{
				mincost = d[i];
				u = i;
			}
		if (mincost == INF)break;
		color[u] = 1;
		for (int i = 0; i < n; i++)
			if (color[i] == 0 && m[u][i] != -1)
				if (d[i] > d[u] + m[u][i])
					d[i] = d[u] + m[u][i];
	}
}
int main()
{
	scanf("%d", &n);
	memset(m, -1, sizeof(m));
	for (int i = 0; i < n; i++)
	{
		int u, k;
		scanf("%d %d", &u, &k);
		for (int i = 0; i < k;i++)
		{
			int v, c;
			scanf("%d%d", &v, &c);
			m[u][v] = c;
		}
	}
	Dijkstra();
	for (int i = 0; i < n; i++)
	{
		printf("%d %d\n", i, d[i]);
	}
	return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;

const int INF = 1 << 30;

struct edge {
	int cost; //重み(距離)
	int to; //行先の頂点
};

void dijkstra(const int n, const vector<vector<edge>> &G, const int stpoint) {

	//優先キューは最短距離と頂点番号のペア、 距離を降順に並べる
	priority_queue<pair<int, int>,vector<pair<int,int>>,greater<pair<int,int>>> pq;

	vector<bool> seen(n,false); //訪問完了でtrue
	vector<int> cost(n,INF); //頂点nまでの距離

	cost[stpoint] = 0;
	pq.push(make_pair(0, 0));

	while (pq.empty() == false) {

		//ターゲット頂点設定（すでに決定したものの中のどれか）
		pair<int, int> target = pq.top();
		int tnum = target.second; //ターゲット頂点番号
		pq.pop();
		
		seen[tnum] = true;

		if (cost[tnum] < target.first) { continue; } //これの意味が分からない保留

		for (unsigned int j = 0; j < G[tnum].size(); j++) { //ターゲットから繋がる先を全部探す

			int v = G[tnum][j].to; //繋がる先の頂点をvにする

			if (seen[v] == true) { continue; } //もう見たとこ（仲間に入ってる）ならスキップ

			if (cost[v] > cost[tnum] + G[tnum][j].cost) {
				cost[v] = cost[tnum] + G[tnum][j].cost;
				pq.push(make_pair(cost[v], v));
			}
		}
	}

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

}

int main() {

	int n;
	cin >> n;

	int stpoint = 0; //この問題では0起点

	vector<vector<edge>> G(n);

	int in1, in2, in3, in4;
	for (int i = 0; i < n; i++) {
		cin >> in1 >> in2;
		for (int j = 0; j < in2; j++) {
			cin >> in3 >> in4;
			G[in1].push_back({ in4, in3 });
		}
	}

	dijkstra(n,G,stpoint);

	return 0;
}