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>
#include<algorithm>
#include<queue>
using namespace std;
static const int MAX = 10000;
static const int INFTY = (1 << 20);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<pair<int, int> > adj[MAX];

void dijkstra() {
	priority_queue<pair<int, int> > PQ;
	int color[MAX], d[MAX];
	for(int i = 0; i < n; i++) {
		color[i] = WHITE;
		d[i] = INFTY;
	}
	
	d[0] = 0;
	PQ.push(make_pair(0, 0));
	color[0] = GRAY;
	
	while(!PQ.empty()) {
        pair<int, int> f = PQ.top();
		PQ.pop();
		int u = f.second;
		
		color[u] = BLACK;
		
		if(d[u] < f.first * (-1)) continue;
		
		for(int j = 0; j < adj[u].size(); j++) {
			int v = adj[u][j].first;
			if(color[v] == BLACK) continue;
			if(d[v] > d[u] + adj[u][j].second) {
				d[v] = d[u] + adj[u][j].second;
				PQ.push(make_pair(d[v] * (-1), v));
				color[v] = GRAY;
			}
		}		
	}
	
	for(int i = 0; i < n; i++) {
		cout << i << " " << (d[i] == INFTY ? -1 : d[i]) << endl;
	} 
}


int main() {
	int u, k, v, c;
	cin >> n;
	for(int i = 0; i < n; i++) {
		cin >> u >> k;
		for(int j = 0; j < k; j++) {
			cin >> v >> c;
			adj[u].push_back( make_pair(v, c));
		}
	}
	
	dijkstra();
	
	return 0;
}

C++: #include <iostream>
#include <cmath>
#include <algorithm>
#include <map>
#include <string>
#include <vector>
#define FOR(i, a, b)  for(int i=a;i<=b;++i)
#define rep(i, n) for(int i=0;i<n;++i)
using namespace std;
struct TRAVEL{
  int to;
  int cost;
};
int main(){
  int n;  cin >> n;
  vector<TRAVEL> g[n];
  int d[n];
  bool flag=true;
  rep(i, n){
    int u, k; cin >> u >> k;
    d[i] = 1000000000;
    rep(j, k){
      int v, c; cin >> v >> c;
      g[i].push_back({v, c});
    }
  }
  d[0] = 0;
  while(flag){
    flag = false;
    rep(i, n){
      rep(j, g[i].size()){
        int check = d[g[i][j].to];
        d[g[i][j].to] = min(d[i]+g[i][j].cost, d[g[i][j].to]);
        if(check != d[g[i][j].to])  flag = true;       }
    }
  }
  rep(i, n) cout << i << " "<< d[i] << endl;
  return 0;
}

C++: #include<iostream>
#include<iomanip>
#include<map>
#include<set>
#include<string>
#include<algorithm>
#include<cmath>
#include<vector>
#include<queue>
#include<stack>
#include<cstring>
#include<sstream>
using namespace std;
 
#define P(p) cout<<(p)<<endl
#define rep(i,m,n) for(int i = (m); i < (int)(n); i++)
#define rrep(i,m,n) for(int i=(int)(m); i>=(int)(n); i--)
#define vsort(v) sort(v.begin(), v.end());
#define rvsort(v) sort(v.begin(), v.end(),greater<int>());
#define YES cout<<"YES"<< endl
#define NO cout<<"NO"<<endl
#define Yes cout<<"Yes"<<endl
#define No cout<<"No"<<endl  
#define yes cout<<"yes"<<endl
#define no cout<<"no"<<endl
#define ret return
#define lb(v,n) lower_bound(v.begin(),v.end(),n)
#define ub(v,n) upper_bound(v.begin(),v.end(),n)
#define mae(v) max_element(v.begin(),v.end())
#define mie(v) min_element(v.begin(),v.end())
#define INF 0x7FFFFFFF
////////////////////////////////////////////////////////////
const int MAX_V = 100;
typedef struct edge_{int to,cost;}edge;
typedef pair<int,int> P; 	//firstは最短経路,secondは頂点番号
int V; 										//頂点数
vector<vector<edge>> G(MAX_V);
int dp[MAX_V];

void dijkstra( int s ){
	//最短経路の値の小さいものから取り出せる
	priority_queue<P,vector<P>,greater<P>> que;
	for(int i = 0 ; i < V ; i++ ) dp[i] = INF;
	dp[s] = 0;
	que.push(pair<int,int>(0,s));
	while(!que.empty()){
		P p = que.top();
		que.pop();
		int v = p.second;
		if( dp[v] > p.first ) continue;
		for(int i = 0 ; i < G[v].size() ; i++ ){
			edge e = G[v][i];
			//cout << "here:" << i << " to:" << e.to << " cost:" << e.cost << endl;
			if( dp[e.to] > dp[v] + e.cost ){
				dp[e.to] = dp[v] + e.cost;
				que.push(pair<int,int>(dp[e.to],e.to));
			}
		}
	}
	return;
}
int main(){
	cin >> V;
		
	rep(i,0,V){
		int u,k;
		cin >> u >> k;
		rep(j,0,k){
			int v,c;
			cin >> v >> c;
			G[i].push_back(edge{v,c});
		}
	}
	
	dijkstra(0);

	rep(i,0,V){
		cout << i << " " << dp[i];
		if( i < V - 1 )
			cout << endl;
	}
	cout << endl;

	ret 0;
}

C++: #include <iostream>
#include <iomanip>
#include <algorithm>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <functional>
#include <sstream>
#include <string>
#include <utility>
#include <map>
#include <memory>
#include <set>
#include <vector>
#include <deque>
#include <list>
#include <stack>
#include <queue>

using namespace std;

class SSSPath
{
public:
  vector<int> v;
  int solve();
};

int SSSPath::solve()
{
  int n;
  cin >> n;

  const int infty = 200000;
  vector<int> d( n, infty );
  
  d[0] = 0;

  vector<vector<int>> adj( n, vector<int>( n, -1 ) );


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

  vector<int> sv( n, true );

  while ( true )
    {
      int md = infty;
      int u;
      
      for ( auto i = 0; i < n; ++i )
        {
          if ( sv[i] && d[i] < md )
            {
              u = i;
              md = d[i];
            }
        }

      if ( md == infty ) break;

      sv[u] = false;
      
      for ( auto i = 0; i < n; ++i )
        {
          if ( sv[i] && adj[u][i] >= 0 )
            {
              if ( d[u] + adj[u][i] < d[i] )
                {
                  d[i] = d[u] + adj[u][i];
                  
                }
            }
          
        }
    }

  for ( auto i = 0; i < n; ++i )
    {
      cout << i << " " << d[i] << endl;
    }
  
  return 0;
}

int main()
{
  SSSPath s;

  s.solve();

  return 0;
}