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>
#include <limits>
#define N 100
#define INF INT_MAX

using namespace std;

int n,M[N][N],d[N];

void dijkstra(int s){
  bool visited[n];
  for(int i=0;i<n;i++){
    visited[i]=false;
    d[i]=INF;
  }
  d[s]=0;
  while(1){
    int mincost=INF;
    int u;
    //find minimum d from non-visited nodes
    for(int i=0;i<n;i++){
      if(!visited[i] && d[i]<mincost){
        mincost=d[i];
        u=i;
      }
    }
    if(mincost==INF) break;

    visited[u]=true;
    //update d
    for(int v=0;v<n;v++){
      if(!visited[v] && M[u][v]!=INF){
        if(d[u]+M[u][v]<d[v]){
          d[v]=d[u]+M[u][v];
        }
      }
    }
  }
}

int main(){
  cin >> n;
  for(int i=0;i<n;i++){
    for(int j=0;j<n;j++) M[i][j]=INF;
  }
  for(int i=0;i<n;i++){
    int u,k; cin >> u >> k;
    for(int i=0;i<k;i++){
      int v,c; cin >> v >> c;
      M[u][v]=c;
    }
  }
  dijkstra(0);
  for(int i=0;i<n;i++)
    cout << i << " " << d[i] << endl;
}

C++: #include<bits/stdc++.h>
using namespace std;
int a[110][110];
int n;
bool visited[110];
int dis[110];
void spfa() {
    int i;
    for(i=0; i<n; i++) {
        dis[i]=1e9+7;
        visited[i]=0;
    }
    queue<int> myqueue;
    while(!myqueue.empty())
    myqueue.pop();
    dis[0]=0;
    visited[0]=1;
    myqueue.push(0);
    int tmp;
    while(!myqueue.empty()) {
        tmp=myqueue.front();
        myqueue.pop();
        visited[tmp]=0;
        for(i=0; i<n; i++)
            if(dis[i]>dis[tmp]+a[tmp][i]) {
                dis[i]=dis[tmp]+a[tmp][i];
                if(!visited[i]) {
                    visited[i]=1;
                    myqueue.push(i);
                }
            }
    }
    return ;
}
int main(){
    scanf("%d",&n);
    int x,t,r,e;
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            a[i][j]=i==j?0:1e9+7;
        }
    }
    for(int i=0;i<n;i++){
        scanf("%d%d",&x,&t);
        while(t--){
            scanf("%d%d",&r,&e);
            if(a[i][r]>e){
                a[i][r]=a[r][i]=e;
            }
        }
    }
    printf("0 0\n");
    spfa();
    for(int i=1;i<n;i++)printf("%d %d\n",i,dis[i]);
}

C++: #include<bits/stdc++.h>
#define ll long long int
#define FOR(i,a,b) for(ll i=(ll)(a);i<(ll)(b);i++)
#define REP(i,n) FOR(i,0,n)
#define REP1(i,n) FOR(i,1,n)
 
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];

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

  REP(i, n) {
    d[i] = INFTY;
    color[i] = white;
  }

  d[0] = 0;
  color[0] = gray;

  while( 1 ) {
    minv = INFTY;
    u = -1;
    REP(i, n) {
      if (minv > d[i] && color[i] != black ) {
        u = i;
        minv = d[i];
      }
    }
    if (u == -1) break;
    color[u] = black;
    REP(v, n) {
      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;
        }
      }
    }
  }
  REP(i, n) {
    cout << i << " " << (d[i] == INFTY ? -1 : d[i]) << endl;
  }
}

int main() {
  cin >> n;
  REP(i, n) {
    REP(j, n) {
      M[i][j] = INFTY;
    }
  }

  int k, c, u, v;
  REP(i, n) {
    cin >> u >> k;
    REP(j, k) {
      cin >> v >> c;
      M[u][v] = c;
    }
  }
  dijkstra();
  return 0;
}

C++: /*宣言*/
#include<cstdio>
#include<iostream>
#include<algorithm>
#include<math.h>
#include<queue>
#include<string.h>
#include<string>
#include<vector>
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
int main()
{
	int n, u, k, w[101][101], v, c;
	int d[101], kas[101] = { 0 }, K;
	cin >> n;
	memset(d, 0x7f, sizeof(d));
	memset(w, 0x7f, sizeof(w));
	rep(i, n)
	{
		cin >> u >> k;
		rep(j, k)
		{
			cin >> v >> c;
			w[u][v] = c;
		}
	}
	d[0]=0;
	int p[101];
	int Min,Min1;
	Min = 0;
	Min1 = 0x7f;
	kas[0] = 1;
	rep(j, n)
	{
		rep(i, n)
		{
			if (d[i] > d[Min] + w[Min][i])
			{
				d[i] = d[Min] + w[Min][i];
				p[i] = Min;
			}
			if (Min1 > d[i] && kas[i] == 0)
			{
				Min1 = d[i];
				K = i;
			}
		}
		kas[K] = 1;
		Min = K;
		Min1 = 0x7f;
	}
	rep(i, n)
	{
		cout << i <<' '<< d[i] << endl;
	}
	return 0;
}

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

#define INF 1000000

int n;
int cost[110][110], d[110];
bool used[110];

void dijkstra(int s){

  //initialization
  for(int i = 0;i < n;i++) d[i] = INF;
  for(int i = 0;i < n;i++) used[i] = false;

  //distance of starting position is 0
  d[s] = 0;
  
  while(true){
    int v = -1;
    
    for(int u = 0;u < n;u++){
      if(!used[u] && (v == -1 || d[u] < d[v])) v = u;
    }
    
    if(v == -1) break; //finish
    used[v] = true; //use v

    //update distance
    for(int u = 0;u < n;u++){
      d[u] = min(d[u], d[v] + cost[v][u]);
    }
  }
}

int main(){
  
  int u, k, v, c;

  //input and initialization
  cin >> n;
  for(int i = 0;i < n;i++){
    for(int j = 0;j < n;j++){
      cost[i][j] = INF;
    }
  }
  for(int i = 0;i < n;i++){
    cin >> u >> k;
    for(int j = 0;j < k;j++){
      cin >> v >> c;
      cost[u][v] = min(cost[u][v], c);
    }
  }
  
  dijkstra(0);

  //output
  for(int i = 0;i < n;i++) cout << i << " " << d[i] << endl;
  
  return 0;
}