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<bits/stdc++.h>
using namespace std;

#define INF 100000000

#define White 0
#define Gray 1
#define Black 2

//重み付き隣接行列
int Tree[100][100];

//ダイクストラ

void dijkstra(int n){
  int u,minv; 

  //d = 最短コスト
  //p = 頂点vの親
  int d[100], p[100], color[100];

  //初期化

  for(int i = 0 ; i < n ; i++){
    d[i] = INF;
    color[i] = White;
  }

  d[0] = 0;
  p[0] = -1;
  color[0] = Gray;

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

    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;

    //地点の更新

    for(int v = 0 ; v < n ; v++){
      if(color[v] != Black && Tree[u][v] != INF){
	if(d[v] > d[u] + Tree[u][v]){
	  d[v] = d[u] + Tree[u][v];
	  color[v] = Gray;
	}
      }
    }
  }
  for(int i = 0 ; i < n ; i++){
    cout << i << " ";
    if(d[i] == INF){
      cout << -1;
    }else{
      cout << d[i];
    }

    cout << endl;
  }
}

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

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

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

  dijkstra(n);

  return 0;
}

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

typedef struct{
  int A[1000];
  int ans;
  bool c;
}node;
node T[1000];
int Q[10000000];
int head=0;
int tail=1;
int n;

void function(int num){
  while(true){
    if(head==tail)break;
    num=Q[head++];
    T[num].c=true;
    for(int i=0;i<n;i++){
      if(T[num].A[i]!=0){
	if(T[i].ans>T[num].ans+T[num].A[i]){
	  T[i].ans=T[num].ans+T[num].A[i];
	Q[tail++]=i;
	}
      }
    }
  }
}

int main(){
  int num,son,z,w;
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>num>>son;
    T[num].ans=INT_MAX;
    for(int j=0;j<son;j++){
      cin>>z>>w;
      T[num].A[z]=w;
      }
  }
  Q[0]=0;
  T[0].ans=0;
  function(0);
 
  for(int i=0;i<n;i++){
      cout<<i<<" "<<T[i].ans<<endl;
  }
  return 0;
}

C++: 
#include<iostream>
#include<cstdio>
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++) {
		printf("%d ", i);
		if (d[i] == INFTY) {
			printf("-1\n");
		}
		else {
			printf("%d\n", d[i]);
		}
	}
}

int main() {
	scanf("%d", &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++) {
		scanf("%d%d", &u, &k);
		for (int j = 0; j < k; j++) {
			scanf("%d%d", &v, &c);
			M[u][v] = c;
		}
	}

	dijkstra();
	return 0;
}

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;
    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 _USE_MATH_DEFINES

#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <map>

using namespace std;

#define MAX_V 200000

typedef pair<long long int, long long int> P;
long long int INF = 1e18;

struct edge{
	int to;
	long long int cost;
};

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

// 速さはO(|E|log|V|)

void shortest_path(int s, int V){ // Vは頂点数
	
	priority_queue<P, vector<P>, greater<P> > que;
	
	for(int i = 0; i < V; i++){
		d[i] = 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] > e.cost + d[v]){
				d[e.to] = d[v] + e.cost;
				que.push(P(d[e.to], e.to));
			}
		} // 頂点への最小コストを更新
	}
}

int main(){
	
	int V;
	cin >> V;
	
	for(int i = 0; i < V; i++){
		int u, num;
		cin >> u >> num;
		for(int j = 0; j < num; j++){
			edge e;
			cin >> e.to >> e.cost;
			G[u].push_back(e);
		}
	}
	
	shortest_path(0, V);
	
	for(int i = 0; i < V; i++){
		cout << i << " " << d[i] << endl;
	}
	
	return 0;
}