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 <map>
#include <vector>
#include <cstdio>
using namespace std;
int main(){
	int n=0,N,i,j,k,c;
	scanf("%d",&N);
	vector<map<int,int> >dist(N);
	vector<bool>used(N);
	vector<int>cost(N);
	for(;n<N;n++){
		cost[n]=99999;
		for(scanf("%d%d",&i,&k);k--;dist[i][j]=c)scanf("%d%d",&j,&c);
	}
	for(cost[0]=0;;){ //dijkstra
		int m=99999;
		for(i=0;i<N;i++)if(!used[i]&&m>cost[i])m=cost[i];
		if(m==99999)break;
		for(j=0;j<N;j++)if(m==cost[j]){
			map<int,int>::iterator it=dist[j].begin();
			for(used[j]=1;it!=dist[j].end();it++)if(cost[it->first]>it->second+cost[j])cost[it->first]=it->second+cost[j];
		}
	}
	for(i=0;i<n;i++)printf("%d %d\n",i,cost[i]);
}

C++: #include<iostream>
#include<cstdio>
#include<climits>
#include<cstring>
#define INF INT_MAX
using namespace std;
typedef unsigned long long ull;
int n;
int A[1000][1000];
ull D[1000][1000];
 
void Init(int f){
  for(int i=0;i<=f+50;i++){
    for(int j=0;j<=f+50;j++)D[i][j] = INF;
  }
 
}
 
int main(){
  scanf("%d",&n);
  int u,k,C,V;
  Init(n);
  
  for(int i=0;i<n;i++){
    scanf("%d %d",&u,&k);    
    for(int j=0;j<k;j++){
      scanf("%d %d",&V,&C);
      D[u][V] = C;
      D[V][u] = C;
    }    
  }
  
  for(int i=0;i<n;i++)D[i][i] = 0;
  for(int k=0;k<n;k++)for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j] = min(D[i][j],D[i][k] + D[k][j]);
  for(int i=0;i<n;i++){
    cout << i << " " << D[0][i] << endl;
  }
 
  return 0;
}

C++: #include<iostream>
#include<vector>
#include<algorithm>
#define MAX_V 100
#define INF 1e9
using namespace std;
int cost[MAX_V][MAX_V];
int d[MAX_V];
bool used[MAX_V];
int V;
void dijkstra(int s) {
	for (int i = 0; i < V; i++) {
		d[i] = INF;
		used[i] = false;
	}
	d[s] = 0;
	while (true) {
		int v = -1;
		for (int u = 0; u < V; u++) {
			if (!used[u] && ((v == -1) || d[u] < d[v])) {
				v = u;
			}
		}
		//全ての頂点が到達済み
		if (v == -1) {
			break;
		}
		//集合に新たに頂点を追加
		used[v] = true;
		for (int u = 0; u < V; u++) {
			d[u] = min(d[u], d[v] + cost[v][u]);
		}
	}
}

int main() {
	for (int i = 0; i < V+100; i++) {
		for (int j = 0; j < V+100; j++) {
			cost[i][j] = INF;//iからjへの辺の重さ
		}
	}
	cin >> V;
	for (int i = 0; i < V; i++) {
		int u;
		cin >> u;
		int k;
		cin >> k;
		for (int j = 0; j < k; j++) {
			int v;
			cin >> v;
			int c;
			cin >> c;
			cost[u][v] = c;
		}
	}
	dijkstra(0);

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

C++: #include <iostream>
#define INF 2000000
#define MAX 100
#define WHITE 0
#define BLACK 1

using namespace std;

int n, d[MAX], color[MAX], w[MAX][MAX];

void dijkstra(int s){
    int u;
    for(u = 0; u < n; u++){
        d[u] = INF;
        color[u] = WHITE;
    }
    d[s] = 0;

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

        for(int v = 0; v < n; v++){
            if(color[v] != BLACK && d[u] + w[u][v] < d[v]){
                d[v] = d[u] + w[u][v];
            }
        }
    }
}

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

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

    dijkstra(0);

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

    return 0;
}

C++: #include<iostream>
#include<algorithm>
#define MAX 120
#define WHITE -1
#define GRAY 0
#define BLACK 1
#define INFTY (1 << 21)

using namespace std;

int n;
int M[MAX][MAX];
int color[MAX], d[MAX], p[MAX];

void dijkstra(){
    
    int mini;
    
    for(int i=0; i<n; i++){
        color[i] = WHITE;
        d[i] = INFTY;
    }
    
    d[0] = 0;
    color[0] = GRAY;
    
    while(1){
        mini = INFTY;
        int u = -1;
        
        for(int i=0; i<n; i++){
            if(mini > d[i] && color[i] != BLACK){
                u=i;
                mini = 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++){
        if(d[i] != INFTY){
            cout << i << " " << d[i] << endl;
        }
        
        //cout << i << " " << d[i] << endl;
    }
    
}


int main(){
    cin >> n;
    
    int k, c, u, v;
    
    for(int i=0; i<n; i++){
        for(int j=0; j<n; j++){
            M[i][j] = INFTY;
        }
    }
    
    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>
#include<vector>
#include<cstdio>
using namespace std;

#define go first
#define ct second

int cost[100 + 10] , cost_ps[100 + 10];
int n,vf,k,v,c;

int v_k[100];

vector< pair<int, int> > went[100];

pair<int, int> p_tmp;

int  check_go(int st)
{
	int i;
	int ret=0;

	for (i = 0; i < v_k[st]; i++)
	{
		if (cost_ps[went[st][i].go] > cost[st] + went[st][i].ct || cost_ps[went[st][i].go] == -1)
		{
			cost_ps[went[st][i].go] = cost[st] + went[st][i].ct;
		}
	}

	for (i = 1; i < n; i++)
	{
		if (cost_ps[ret] > cost_ps[i] && cost[i]==-1 && cost_ps[i]!=-1 || cost[ret] != -1 )
		{
			ret = i;
			//printf("ret=%d\n", ret);
		}
	}

	cost[ret] = cost_ps[ret];
	//cout << "A" << cost[ret] << endl;

	return ret;

}

int main()
{
	int i,j;
	int st_num=0;

	cin >> n;

	for (i = 0; i < n; i++)
	{
		cost[i] = cost_ps[i] = -1;

		cin >> vf ;
		cin >> v_k[vf];
		for (j = 0; j < v_k[vf] ; j++)
		{
			cin >> p_tmp.go >> p_tmp.ct;

			went[vf].push_back(p_tmp);
		}
	}

	cost[0] = cost_ps[0] = 0;

	for (i = 1; i < n; i++)
	{
		st_num = check_go(st_num);
	}

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

	return 0;
}