Go: package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
)

type Item struct {
	value    int // The value of the item; arbitrary.
	priority int // The priority of the item in the queue.
	// The index is needed by update and is maintained by the heap.Interface methods.
	index int // The index of the item in the heap.
}
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }
func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].priority < pq[j].priority
}
func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = i
	pq[j].index = j
}
func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}
func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	item.index = -1 // for safety
	*pq = old[0 : n-1]
	return item
}

type Q struct {
	pq *PriorityQueue
	ds map[int]int // It has always same value as pq. For random access.
}

func newQ() *Q {
	pq := new(PriorityQueue)
	heap.Init(pq)
	return &Q{
		pq: pq,
		ds: make(map[int]int),
	}
}
func (q *Q) pop() (u, d int) {
	item := heap.Pop(q.pq).(*Item)
	delete(q.ds, item.value)
	return item.value, item.priority
}
func (q *Q) get(u int) (int, bool) { // returns d
	d, ok := q.ds[u]
	return d, ok
}
func (q *Q) set(u, d int) {
	q.ds[u] = d
	for _, item := range *q.pq {
		if item.value != u {
			continue
		}

		item.priority = d
		heap.Fix(q.pq, item.index)
		return
	}
	heap.Push(q.pq, &Item{
		priority: d,
		value:    u,
	})
}
func (q *Q) len() int {
	return len(q.ds)
}

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

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

		out[u] = d
		visited[u] = struct{}{}
	}

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

C++: #include <stdio.h>
#define INF (1<<21)

int main(void)
{
 int i,j,n,m,u,k,l,v,c,a[10000],b[10000],d[10000][10000];

 scanf("%d",&n);
 
 for(i=0;i<n;i++){
 	scanf("%d %d",&u,&k);
 	a[i]=INF;
 	b[i]=0;
 	for(j=0;j<k;j++){
 		scanf("%d %d",&v,&c);
 		d[u][v]=c;
 	}
 }
 a[0]=0;
 
 while(1){
 	
 	l=-1;
 	m=INF;
 	
 	for(i=0;i<n;i++){
 		if(a[i]<m && b[i]==0){
 			m=a[i];
 			l=i;
 		}
 	}
 	
 	if(l==-1) break;
 	
 	b[l]=1;
 	
 	for(i=0;i<n;i++){
 		if(a[i]>=d[l][i]+a[l]) a[i]=d[l][i]+a[l];
 	}
 }
 
 for(i=0;i<n;i++){
 	if(a[i]==INF) printf("%d -1\n",i);
 	else printf("%d %d\n",i,a[i]);
 }
 
 return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

#define INF 1<<29
#define MAXV 100

int V;      //????????°
int cost[MAXV+10][MAXV+10];

vector<int> dijkstra(int s){
    vector<int> d(V,INF);
    bool used[MAXV+10];
    for(int i=0;i<MAXV+10;i++) used[i]=false;

    d[s]=0;
    while(true){
        //??????????????????????????????????????§s??????????????¢???????°?????????????v??¨??????
        int v=-1;
        for(int u=0;u<V;u++){
            if(!used[u] and (v==-1 or d[u]<d[v])) v=u;
        }

        if(v==-1) break;
        
        used[v]=true;
        for(int u=0;u<V;u++){
            d[u] = min(d[u],d[v]+cost[v][u]);
        }
    }
    return d;
}

int main(){
    // initialize
    for(int i=0;i<MAXV+10;i++) for(int j=0;j<MAXV+10;j++) cost[i][j]=INF;

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

    vector<int> dis = dijkstra(0);
    for(int i=0;i<dis.size();i++){
        printf("%d %d\n",i,dis[i]);
    }
}

C++: #include<iostream>
#include<cstdio>
#include<algorithm>

#define MAX 100
static const int INFTY =(1<<21);

int n,M[MAX][MAX];
int unvisited=0,decide=1,comp_decide=2;

void dijkstra(){
	int d[MAX];
	int state[MAX];
	for(int i=0;i<n;i++){
		d[i]=INFTY;
		state[i]=unvisited;
	}
	d[0]=0;
	state[0]=0;
	while(1){
		int mincost=INFTY,u=-1;
		for(int i=0;i<n;i++){
			if(d[i]<mincost&&state[i]!=comp_decide){
				u=i;
				mincost=d[i];
			}
		}
		if(u==-1) break;
		state[u]=comp_decide;
		for(int v=0;v<n;v++){
			if(state[v]!=comp_decide&&M[u][v]!=INFTY){
				if(d[v]>d[u]+M[u][v]){
					d[v]=d[u]+M[u][v];
					state[v]=decide;
				}
			}
		}
	}
	for(int i=0;i<n;i++){
			printf("%d %d\n",i,(d[i]==INFTY ? -1:d[i]));
	}
}

int main(){
	scanf("%d",&n);
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			M[i][j]=INFTY;
		}
	}
	int u,k,v,c;
	for(int i=0;i<n;i++){
		scanf("%d %d",&u,&k);
		for(int j=0;j<k;j++){
			scanf("%d %d",&v,&c);
			M[u][v]=c;
		}
	}
	dijkstra();
}

C++: #include<iostream>
#define INF 1<<30
using namespace std;
int main() {
  int n; cin >> n;
  int graph[100][100];
  for (int i = 0; i < n; ++i)
    for (int j = 0; j < n; ++j) graph[i][j] = INF;
  for (int i = 0; i < n; ++i) {
    int u, k, v; cin >> u >> k;
    for (int j = 0; j < k; ++j) {
      cin >> v;
      cin >> graph[u][v];
    }
  }
  int mincost[100], flag[100] = {};
  mincost[0] = 0;
  for (int i = 1; i < n; ++i) mincost[i] = INF;
  while (1) {
    int x = -1;
    for (int i = 0; i < n; ++i)
      if (!flag[i] && (x == -1 || mincost[x] > mincost[i])) x = i;
    if (x == -1) break;
    flag[x] = 1;
    for (int i = 0; i < n; ++i)
      if (mincost[i] > mincost[x]+graph[x][i]) mincost[i] = mincost[x]+graph[x][i];
  }
  for (int i = 0; i < n; ++i) cout << i << " " << mincost[i] << endl;
  return 0;
}

C++: #include <iostream>
#include <string>
#include <unordered_map>
#include <stdio.h>
#include <list>
#include <vector>
#include <algorithm>
#include <stack>
#include <climits>
#include <queue>
using namespace std;
#define rep(i, n) for(int i = 0; i < n; ++i)
typedef long long ll;

int M[100][100];

int main()
{
	int n;cin >> n;
	rep(i,n)
		rep(j,n)M[i][j]=INT_MAX;
		
	rep(i,n)
	{
		int hoge, hogege;
		cin >> hoge >> hogege;
		rep(j,hogege)
		{
			int foo,fooo;
			cin >> foo >> fooo;
			M[i][foo]=fooo;
		}
	}

	vector<int> color(n);
	rep(i,n)color[i]=0;
	vector<int> d(n);
	rep(i,n)d[i]=INT_MAX;
	vector<int> p(n);
	d[0]=0;
	p[0]=-1;

	while (1)
	{
		int u;
		int mincost = INT_MAX;
		rep(i,n)
		{
			if((color[i]!=2)&&(d[i]<mincost))
			{
				mincost=d[i];
				u=i;
			}
		}

		if(mincost==INT_MAX)break;

		color[u] = 2;

		rep(v,n)
		{
			if(color[v] != 2&&M[u][v]!=INT_MAX)
			{
				if(d[u] + M[u][v] < d[v])
				{
					d[v] = d[u] + M[u][v];
					p[v] = u;
					color[v] = 1;
				}
			}
		}
	}
	rep(i,n)
	{
		cout<<i<<" "<<d[i]<<endl;
	}


	

	return 0;
}