Go: package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"os"
	"strconv"
	"strings"
)

const (
	INFTY = 1 << 21
	NIL   = -1
)

const (
	WHITE = iota
	GRAY
	BLACK
)

type Graph [][]int

func (g *Graph) dikstra(n int) string {
	var (
		u, minv = 0, 0
	)

	d := make([]int, n)
	color := make([]int, n)

	for i := 0; i < n; i++ {
		d[i] = INFTY
		color[i] = WHITE
	}
	d[0] = 0
	color[0] = GRAY

	for {
		minv = INFTY
		u = -1
		for 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 v := 0; v < n; v++ {
			if color[v] != BLACK && (*g)[u][v] != INFTY {
				if d[v] > d[u]+(*g)[u][v] {
					d[v] = d[u] + (*g)[u][v]
					color[v] = GRAY
				}
			}
		}
	}

	var out bytes.Buffer
	for i := 0; i < n; i++ {
		out.WriteString(fmt.Sprintf("%d ", i))
		if d[i] == INFTY {
			out.WriteString(fmt.Sprintf("%d\n", -1))
			continue
		}
		out.WriteString(fmt.Sprintf("%d\n", d[i]))
	}

	return strings.TrimRight(out.String(), "\n")
}

func answer(reader io.Reader) string {
	sc := bufio.NewScanner(reader)
	sc.Split(bufio.ScanWords)

	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())

	g := make(Graph, n)
	for i := 0; i < n; i++ {
		g[i] = make([]int, n)
		for j := 0; j < n; j++ {
			g[i][j] = INFTY
		}
	}

	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())

		for j := 0; j < k; j++ {
			sc.Scan()
			v, _ := strconv.Atoi(sc.Text())
			sc.Scan()
			c, _ := strconv.Atoi(sc.Text())

			g[u][v] = c
		}
	}

	return g.dikstra(n)
}

func main() {
	fmt.Println(answer(os.Stdin))
}

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

static const int MAX=100;
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;
static const int INF=(1<<21);

int n,M[MAX][MAX];

void dig(){
  int color[MAX],d[MAX];
  for(int i=0;i<n;i++){
    color[i]=WHITE;
    d[i]=INF;
  }


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

int minc,u;
while(1){
  minc=INF;
  u=-1;
  for(int i=0;i<n;i++){
    if(color[i]!=BLACK&&minc>d[i]){
      minc=d[i];
      u=i;
    }
  }
if(u==-1) break;
  color[u]=BLACK;

  for(int v=0;v<n;v++){
    if(M[u][v]!=INF&&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]==INF?-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]=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;
      M[u][v]=c;
    }
  }

  dig();
  return 0;
}

C++: #include<iostream>
using namespace std;
static const int INF=(1<<21);
int M[100][100];
void dij(int n, int d[], int color[]){
	d[0]=0;
	color[0]=1;
	int minv;
	while(1){
		minv=INF;
		int u=-1;
		for(int i=0; i<n; i++){
			if(minv>d[i] && color[i]!=2){
				u=i;
				minv=d[i];
			}
		}
		if(u==-1)
			break;
		color[u]=2;
		for(int v=0; v<n; v++){
			if(color[v] !=2 & M[u][v]!=INF){
				if(d[v]>d[u]+M[u][v]){
					d[v]=d[u]+M[u][v];
					color[v]=1;
				}
			}
		}
	}
}
int main(){
	int n;
	cin>>n;
	for(int i=0; i<n; i++){
		for(int j=0; j<n; j++){
			M[i][j]=INF;
		}
	}
	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;
		}
	}
	int d[n], color[n];
	for(int i=0; i<n; i++){
		d[i]=INF;
		color[i]=0;
	}
	dij(n, d, color);
	for(int i=0; i<n; i++){
		cout<<i<<" ";
		if(d[i]==INF)
			cout<<-1<<endl;
		else
			cout<<d[i]<<endl;
	}
	return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cassert>
#include <string>
#include <cstring>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <algorithm>

using namespace std;

// ---------------------
// repetition
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)

// debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

// ---------------------
#define INF (1 << 21)
typedef long long ll;

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

  vector<int> V[n];
  int E[n][n];
  int d[n];
  int visited[n];

  REP(x, n) {
    REP(y, n) {
      E[x][y] = INF;
    }
    d[x] = INF;
    visited[x] = 0;
  }

  REP(_, n) {
    int u, k;
    cin >> u >> k;
    REP(__, k) {
      int v, c;
      cin >> v >> c;
      V[u].push_back(v);
      E[u][v] = c;
      // E[v][u] = c;
    }
  }

  d[0] = 0;
  REP(_, n) {
    int minv = -1;
    int mincost = INF;
    REP(v, n) {
      if (!visited[v] && d[v] < mincost) {
        minv = v;
        mincost = d[v];
      }
    }
    visited[minv] = 1;
    for (vector<int>::iterator it = V[minv].begin(); it != V[minv].end(); it++) {
      if (E[minv][*it] < INF && d[minv] + E[minv][*it] < d[*it]) {
        d[*it] = d[minv] + E[minv][*it];
      }
    }
  }

  REP(i, n) {
    cout << i << " " << d[i] << endl;
  }
  return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
const int INF=(int)1e9;

int main(){
    //入力パート
    int n; cin>>n;
    vector<pair<int,int>> tonari[110]; //隣接リスト 一つ目が行先の頂点で二つ目が辺のコスト
    vector<int> dist(n,INF); //各頂点の（暫定）最短距離を格納
    vector<bool> det(n,false); //各頂点の最短距離が確定しているか格納
    for(int i=0;i<n;++i){
        int u,k,c,v;
        cin>>u>>k;
        for(int j=0;j<k;++j){
            cin>>c>>v;
            tonari[u].push_back(make_pair(c,v));
        }
    }
    //探索パート
    dist[0]=0; //出発地点の最短距離は0
    for(int i=0;i<n;++i){
        int mini=INF,mini_node=-1; //未確定点の最短距離とその頂点番号を格納
        for(int j=0;j<n;++j){ //最短距離が最小の点を探索
            if(det[j]) continue; //確定している点は対象外
            if(dist[j]<mini){
              mini=dist[j];
              mini_node=j;
            }
        }
        det[mini_node]=true; //最短距離を確定させる
        for(pair<int,int> tsugi:tonari[mini_node]){
            dist[tsugi.first]=min(dist[tsugi.first],dist[mini_node]+tsugi.second); //隣接ノードの値の更新
        }
    }
    
    //出力パート
    for(int i=0;i<n;++i){
        cout<<i<<" "<<dist[i]<<endl;
    }
    return 0; 
}

C++: #include <iostream>
using namespace std;
 
#define MAX   100
#define INFTY (1 << 21)
#define WHITE 0
#define GRAY  1
#define BLACK 2
 
int n, M[MAX][MAX];
 
void dijkstra() {
  int d[MAX], p[MAX], color[MAX];
  int minv, u;
  for ( int i = 0; i < n; i++ ) {
    d[i] = INFTY;
    p[i] = -1;
    color[i] = WHITE;
  }
 
  d[0] = 0;
color[0] = GRAY;
  while ( 1 ) {
    minv = INFTY;
    u = -1;
    for ( int i = 0; i < n; i++ ) {
      if ( minv > d[i] && color[i] != BLACK ) {
        minv = d[i];
u = 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;
}