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 static int MAX = 100;
const static int INFTY = (1<<21);
const static int WHITE = 0;
const static int GRAY = 1;
const static 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(true){
    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 <iostream>
#include <cstdlib>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <set>
#include <string>
#include <cmath>
using namespace std;

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define REP(i, k, n) for (int i = (int)(k); i < (int)(n); i++)
#define rrep(i, n) for (int i = (int)(n)-1; i >= 0; i--)
#define rREP(i, k, n) for (int i = (int)(n)-1; i >= k; i--)

#define debug(x) cerr<<#x<<": "<<x<<'\n'

#define fi first
#define se second

#define vi vector<int>
#define pb push_back
#define mp make_pair

#define pcnt __builtin_popcount

typedef long long ll;

const int inf = 100100100;
const int MOD = (int)1e9 + 7;
const double EPS = 1e-9;
int G[110][110] = {};
int d[110] = {};
int main(){
    int n;
    cin >> n;
    rep(i,n)rep(j,n) G[i][j]=-1;
    rep(i,n){
        int t,m;
        cin >> t >> m;
        rep(j,m){
            int a,b;
            cin >> a >> b;
            G[t][a] = b;
        }
    }

    rep(i,n) d[i] = 900010000;
    d[0] = 0;
    while(true){
        bool update = false;
        rep(i,n){
            rep(j,n){
                if(i==j) continue;
                if(G[i][j] != -1 && d[i] + G[i][j] < d[j]){
                    d[j] = d[i]+G[i][j];
                    update = true;
                }
            }
        }
        if(!update) break;
    }

    rep(i,n){
        cout << i << " " << d[i] << endl;
    }

    return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <queue>
#include <vector>
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];
    int d[MAX];
    for(int i = 0; i<n; i++){
        d[i] = INFTY;
        color[i] = WHITE;
    }

    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;
                //priority_queue ?????????????????§??????????????????-1
                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 k,u,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();
}

C++: #include<vector>
#include<iostream>
#include<algorithm>
#define MAX_V 100
#define INF 1e9
using namespace std;
int V;
int d[MAX_V];
int cost[MAX_V][MAX_V];
bool used[MAX_V];

void dijkstra(int s)
{
	while (true)
	{
		int v = -1;
		for (int u = 0; u < V; u++)
		{
			if (!used[u] && (v == -1 || d[u] < d[v]))
			{
				v = u;
			}
		}
		if (v == -1)
		{
			break;
		}
		used[v] = true;

		for (int u = 0; u < V; u++)
		{
			if (cost[v][u] = INF)
			{
				continue;
			}
			d[u] = min(d[u], d[v] + cost[v][u]);
		}
	}

}
int main()
{
	cin >> V;
	for (int i = 0; i < MAX_V; i++)
	{
		for (int j = 0; j < MAX_V; j++)
		{
			cost[i][j] = INF;
		}
	}
	for (int i = 0; i < MAX_V;i++)
	{
		d[i] = INF;
		used[i] = false;
	}
	for (int i = 0; i < V; i++)
	{
		int u;
		cin >> u;
		int k;
		cin >> k;
		for (int j = 0; j < k; i++)
		{
			int v_to;
			cin >> v_to;
			int c;
			cin >> c;

			cost[u][v_to] = c;

		}
	}

	dijkstra(0);

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

	return 0;

}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <string>
#include <cmath>
#include <vector>
#include <queue>
#include <climits>
typedef long long ll;
using namespace std;

struct Dijkstra{
  int n,i;
  vector<vector<pair<int,int> > > edge; //cost,to
  vector<int> distance;
  vector<int> prev;

  void init(int v){
    n=v;
    edge.resize(n);
    distance.resize(n);
    prev.resize(n);
  }

  void calc(int start){
    for(i=0;i<n;i++){
      distance[i]=INT_MAX;
      prev[i]=-1;
    }
    distance[start]=0;

    priority_queue<pair<int,int> > q; //cost,to
    int from,to,tmp;
    q.push({0,start});

    while(!q.empty()){
      from=q.top().second;
      q.pop();
      for(i=0;i<edge[from].size();i++){
        int to=edge[from][i].second;
        int tmp=distance[from]+edge[from][i].first;
        if(distance[to]>tmp){
          distance[to]=tmp;
          prev[to]=from;
          q.push({tmp,to});
        }
      }
    }

  }
};

int main(void){
  int n,u,k,v,c,i,j;
  Dijkstra graph;
  cin>>n;
  graph.init(n);
  for(i=0;i<n;i++){
    cin>>u>>k;
    for(j=0;j<k;j++){
      cin>>v>>c;
      graph.edge[u].push_back({c,v});
    }
  }
  graph.calc(0);

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

  return 0;
}