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>
using namespace std;

static const int MAX = 100; //頂点数の最大値100まで対応可能
static const int INFTY = (1<<21);   //適当な値で\inftyを表す
static const int WHITE = 0; //未訪問の頂点を白色で表す
static const int GRAY = 1; //その時点で決定された最短経路木Sに属する
static const int BLACK = 2; //訪問済みの頂点を黒色で表す

int n, M[MAX][MAX]; //Mはuからvへの辺の重みを記録する隣接行列

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

    for(int i = 0; i < n; i++){
        d[i] = INFTY; //すべての頂点について最短コストを\inftyで初期化しておく（最短経路探索問題だから）
        color[i] = WHITE; //すべての頂点を未訪問としておく
    }

    d[0] = 0; //スタート地点からスタート地点までの距離は0
    color[0] = GRAY; //スタート地点をSに所属させる
    while(1){
        minv = INFTY;
        int u = -1; //最初0の親を-1にしておく
        for(int i = 0; i < n; i++){ 
            if(minv > d[i] && color[i] != BLACK){  //頂点が訪問済みでなく, かつ, スタート地点からiまでの最短コストがminv未満
                u = i; //最短コストを取る点をiへと更新する
                minv = d[i]; //最短コストをd[i]へと更新する
            }
        }
        
        //　V/Sの中でd[u]が最小となる点uの選択が完了した.

        if(u==-1) break;
        color[u] = BLACK; //uを訪問済みにするs
        for(int v = 0; v < n; v++){
            if(color[v] != BLACK && M[u][v] != INFTY){ //vが未訪問の点であり, かつuとvの間にedgeが存在する
                if(d[v] > d[u] + M[u][v]){ //uからedgeを通りvへ向かう距離の方が, それまでのd[v]より小さいならば
                    d[v] = d[u] + M[u][v]; //d[v]の値を更新する
                    color[v] = GRAY; //vを決定された最短経路木Sに属させる
                }
            }
        }
    }

    for(int i = 0; i < n; i++){
        cout << i << " " << (d[i] == INFTY ? -1 : d[i]) << endl; //距離が\inftyか?? 
    }
}

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; //頂点番号を出次数を入力する
        for(int j = 0; j < k; j++){
            cin >> v >> c;
            M[u][v] = c; //有効辺の重みを入力する
        }
    }

    dijkstra(); //Dijkstra法を実施する
    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++: #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++: #include <iostream>
using namespace std;

#define MAX_SIZE 110
#define INF (1<<30)
#define NOT_VISITED 0
#define VISITED 1
#define COMPLETE 2

int n, G[MAX_SIZE][MAX_SIZE];
int d[MAX_SIZE], status[MAX_SIZE];

void dijkstra() {
    for (int i = 0; i < n; i++) {
        d[i] = INF;
        status[i] = NOT_VISITED;
    }
    d[0] = 0;

    int u, min_cost;
    while (1) {
        u = -1;
        min_cost = INF;
        for (int i = 0; i < n; i++) {
            if (min_cost > d[i] && status[i] != COMPLETE) {
                u = i;
                min_cost = d[i];
            }
        }
        if (u == -1) break;
        status[u] = COMPLETE;
        for (int i = 0; i < n; i++) {
            if (status[i] == COMPLETE || G[u][i] == INF) continue;
            if (d[i] > d[u] + G[u][i]) {
                d[i] = d[u] + G[u][i];
                status[i] = VISITED;
            }
        }
    }
    
    return;
}

void print() {
    for (int i = 0; i < n; i++) {
        cout << i << " ";
        if (d[i] == INF) cout << -1;
        else cout << d[i];
        cout << endl;
    }
    return;
}

int main() {
    cin >> n;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            G[i][j] = INF;
        }
    }

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

    dijkstra();

    print();

    return 0;
}