Go: package main

import (
	"bufio"
	"fmt"
	"os"
)

func main() {
	r := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(r, &n)
	cs := make([]map[int]int, n) // []v_i -> c_i
	for h := 0; h < n; h++ {
		var u, k int
		fmt.Fscan(r, &u, &k)
		m := make(map[int]int)
		for i := 0; i < k; i++ {
			var v, c int
			fmt.Fscan(r, &v, &c)
			m[v] = c
		}

		cs[u] = m
	}

	q := make(map[int]int)
	q[0] = 0
	visited := make(map[int]struct{})
	out := make([]int, n)

	for len(q) > 0 {
		u := top(q)
		for uu, c := range cs[u] {
			// Consider the connection between u and uu.
			if _, ok := visited[uu]; ok {
				continue
			}
			if d, ok := q[uu]; !ok || d > q[u]+c {
				q[uu] = q[u] + c
			}
		}

		out[u] = q[u]
		delete(q, u)
		visited[u] = struct{}{}
	}

	for u, d := range out {
		fmt.Println(u, d)
	}
}

func top(q map[int]int) int {
	minu := -1
	min := -1
	for u, d := range q {
		if min < 0 || d < min {
			minu = u
			min = d
		}
	}

	return minu
}

C++: #include<iostream>
using namespace std;
const int MAX = 100;
const int INFTY = (1<<21);
const int WHITE = 0;
const int GRAY = 1;
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] + 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 <bits/stdc++.h>
using namespace std;
#define MAX 1000000000

int main(void){
  ios::sync_with_stdio(false);
  cin.tie(0);

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

  vector<int> d(n,MAX);
  vector<bool> used(n, false);
  d[0] = 0;
  while(true){
    int t = -1;
    for(int i = 0; i < n; i++){
      if(!used[i] && (t == -1 || d[t] > d[i])) t = i;
    }
    if(t == -1) break;
    used[t] = true;

    for(int i = 0; i < n; i++){
      d[i] = min(d[i], d[t] + f[t][i]);
    }
  }

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