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 <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>

#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define repi(i,a,b) for(int i = (a); i < (b); i++)

using namespace std;

typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;

const int INF=1<<29;
const double EPS=1e-9;

const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};
const int MAX_N =10000;

struct edge
{
	int to,cost;
	edge(int _to,int _cost){
		to =_to;
		cost =_cost;
	}
};

int V;
vector<edge> cost[MAX_N];
int d[MAX_N];
bool visit[MAX_N];
void dijkstra(int s){
	d[s]=0;
	priority_queue<pii, vector<pii> ,greater<pii> > que;
	que.push(mp(0,s));
	while(!que.empty()){
		pii p =que.top();
		que.pop();
		int v =p.second;
		//if(d[v] != p.first)continue;
		for(int i =0;i <cost[v].size();i++){
			edge e =cost[v][i];
			if(d[e.to] >d[v]+e.cost){
				d[e.to] =d[v] +e.cost;
				que.push(mp(d[e.to],e.to));
			}
		}
	}
}

int main(){
	cin>>V;
	for(int i =0;i <V;i++){
		d[i]=INF;
		int u,k;
		cin>>u>>k;
		for(int j =0;j <k;j++){
			int to,c;
			cin>>to>>c;
			cost[u].push_back(edge(to,c));
		}
	}
	
	dijkstra(0);
	for(int i =0;i <V;i++){
		cout <<i<<" "<<d[i]<<endl;
	}
	return 0;
}

C++: #include <iostream>
#include <vector>
using namespace std;
typedef unsigned short ushort;
typedef vector <int> vi;
typedef vector <vi> vvi;

class blanch{
	public:
		bool visited;
		int distance;
		ushort from;
};
typedef vector <blanch> vb;

int make_graph(vvi &graph, vb &nodes){
	int n=graph.size();
	for (int i=0; i<n; i++){
		for (int j=0; j<n; j++){
			graph[i][j]=-1;
		}
		nodes[i].visited = false;
		nodes[i].distance = INT_MAX;
	}

	for (int i=0; i<n; i++){
		int i2,n2;
		cin>>i2;
		cin>>n2;
		for (int j=0; j<n2; j++){
			int j2;
			cin>>j2;
			cin>>graph[i2][j2];
		}
	}
	return 0;
}

int Shortest_Path(vvi &graph, vb &nodes){

	int n = graph.size(), p1=0;
	nodes[p1].distance = 0;

	while (p1 != -1){
		nodes[p1].visited=true;
		cout<<"node: "<<p1<<", distance: "<<nodes[p1].distance<<endl;
		for (int p2 = 0; p2 < n; p2++){
			int *tmp = &graph[p1][p2];
			if (*tmp!=-1 && nodes[p2].visited==false){
				int tmp2 = *tmp + nodes[p1].distance;
				if (tmp2 < nodes[p2].distance){
					nodes[p2].distance = tmp2;
					nodes[p2].from = p1;
				}
			}
		}

		p1 = -1;
		int tmp;
		tmp = INT_MAX;
		for (int i=0; i<n; i++){
			if (nodes[i].visited==false && nodes[i].distance<tmp){
				p1 = i;
				tmp = nodes[i].distance;
			}
		}
	}
	return 0;
}

int resultout(vb &nodes){
	int n = nodes.size();
	for (int i=0; i<n; i++){
		cout<<i<<" "<<nodes[i].distance<<endl;
	}
	return 0;
}

int main(void){

	int n;
	cin>>n;
	vvi G(n, vi(n));
	vb nodes(n);

	make_graph(G, nodes);

	Shortest_Path(G, nodes);

	resultout(nodes);

	return 0;
}

C++: #include <iostream>
#include <vector>
#include <queue>
 
using namespace std;
 
struct adja {
    int v;
    int c;
};
 
int n;
vector<adja> g[10000];
int d[10000];
 
void search() {
    fill_n(d, n, 1 << 20);
    queue<int> q;
    q.push(0);
    d[0] = 0;
    while (!q.empty()) {
        int u = q.front();
        q.pop();
        for (int i = 0, s = g[u].size(); i < s; ++i) {
            if (d[g[u][i].v] > d[u] + g[u][i].c) {
                d[g[u][i].v] = d[u] + g[u][i].c;
                q.push(g[u][i].v);
            }
        }
    }
}
 
int main() {
    int u, k, v, c;
    cin >> n;
    for (int i = 0; i < n; ++i) {
        cin >> u >> k;
        g[u].resize(k);
        for (int j = 0; j < k; ++j) {
            cin >> g[u][j].v >> g[u][j].c;
        }
    }
    search();
    for (int i = 0; i < n; ++i) {
        cout << i << " " << d[i] << endl;
    }
 
    return 0;
}

C++: #include<bits/stdc++.h>
#define REP(i,n) for(int i=0;i<(int)(n);i++)
typedef long long int ll;
using namespace std;

const int MAX_V = 10000;
const int INF=1e9;

int cost[MAX_V][MAX_V];
int d[MAX_V];
bool used[MAX_V];
int n;

void dijkstra(int s){
  fill(d,d+n,INF);
  fill(used, used+n,false);
  d[s]=0;
  while(true){
    int v=-1;
    REP(u,n)
      if(!used[u] && (v==-1 || d[u]<d[v]))
	v=u;
    if(v==-1) break;
    used[v]=true;
    REP(u,n) d[u]=min(d[u],d[v]+cost[v][u]);
  }
}

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