Go: package main

import (
	"strconv"
	"fmt"
	"bufio"
	"os"
)
const INF = 1 << 21
var scanner = bufio.NewScanner(os.Stdin)

func nextInt() int {
	scanner.Scan()
	i, e := strconv.Atoi(scanner.Text())
	if e != nil {
		panic(e)
	}
	return i
}


func main() {
	scanner.Split(bufio.ScanWords)
	n := nextInt()
	adj := make([][]int, n)
	for i := range adj {
		adj[i] = make([]int, n)
	}

	for i := 0;i < n; i++ {
		u := nextInt()
		k := nextInt()
		for j := 0; j < k; j++ {
			v := nextInt()
			c := nextInt()
			adj[u][v] = c
		}
	}

	// for i := range adj {
	// 	fmt.Println(adj[i])
	// }

	dist := make([]int, n)
	prev := make([]int, n)
	visited := make([]bool, n)
	dijkstra := func(start int, size int) {
		for i := 0; i < size; i++ {
			dist[i] = INF
			prev[i] = -1
			visited[i] = false
		}
		dist[start] = 0
		for {
			u := -1
			tmp_min := INF
			for i := 0; i < size; i++ {
				if visited[i] == false && dist[i] < tmp_min {
					tmp_min = dist[i]
					u = i
				}
			}
			if u == -1 {
				break
			}
			visited[u] = true
			for i := 0; i < size; i++ {
				if adj[u][i] > 0 {
					w := adj[u][i]
					newlen := dist[u] + w
					if newlen < dist[i] {
						dist[i] = newlen
						prev[i] = u
					}
				}
			}
		}
	}
	dijkstra(0, n)
	for i, cost := range dist {
		fmt.Printf("%d %d\n", i, cost)
	}
}

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 min;
   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 ) {
      min = INFTY; 
      int a = -1;
      for ( int i = 0; i < n; i++ ) {
         if ( min > d[i] && color[i] != BLACK ) {
             a = i;
             min = d[i];
         }
      }
 
      if ( a == -1 ) break;
      color[a] = BLACK;
       
      for ( int v = 0; v < n; v++ ) {
         if ( color[v] != BLACK && M[a][v] != INFTY ) {
            if ( d[v] > d[a] + M[a][v] ) {
               d[v] = d[a] + M[a][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 < n; 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][v]+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>
#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;
}