Go: package main

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

const NIL = -1

type Node struct {
	id     int
	weight int
}

func init() {
	sc.Split(bufio.ScanWords)
}

type NodeHeap []Node

func (h NodeHeap) Len() int           { return len(h) }
func (h NodeHeap) Less(i, j int) bool { return h[i].weight < h[j].weight }
func (h NodeHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *NodeHeap) Push(x interface{}) {
	*h = append(*h, x.(Node))
}

func (h *NodeHeap) Pop() interface{} {
	old := *h
	n := len(old)
	x := old[n-1]
	*h = old[0 : n-1]
	return x
}

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func main() {
	n := scanInt()

	list := make([][]int, n)
	weight := make([]int, n)
	for i := range list {
		list[i] = make([]int, n)
		weight[i] = NIL
		for j := range list[i] {
			list[i][j] = NIL
		}
	}

	for i := 0; i < n; i++ {
		u := scanInt()
		k := scanInt()
		for j := 0; j < k; j++ {
			v := scanInt()
			w := scanInt()
			list[u][v] = w
		}
	}

	start := Node{id: 0, weight: 0}
	h := &NodeHeap{start}
	heap.Init(h)

	for h.Len() > 0 {
		node := heap.Pop(h).(Node)
		if weight[node.id] != NIL {
			continue
		}
		weight[node.id] = node.weight

		for i, w := range list[node.id] {
			if w == NIL {
				continue
			}
			heap.Push(h, Node{id: i, weight: w + node.weight})
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		fmt.Fprint(w, i)
		fmt.Fprint(w, " ")
		fmt.Fprint(w, weight[i])
		fmt.Fprintln(w)
	}
	w.Flush()
}

C++: #include <iostream>
#include <cstring>
#define MAX 120000
using namespace std;

int matrix[105][105],n,closest[105],close[105];

void djst(){
    int i,j,k;
    for(i=1;i<n;i++){
        if(matrix[0][i]!=-1)close[i]=matrix[0][i];
    }
    while(1){
        int mi=MAX,rec=-1;
        for(i=1;i<n;i++){
            if(close[i]!=-1&&close[i]<mi&&closest[i]==-1){
                mi=close[i];
                rec=i;
            }
        }
        if(rec==-1)break;
        closest[rec]=mi;
        close[rec]=MAX;
        for(j=1;j<n;j++){
            if(closest[j]==-1&&matrix[rec][j]!=-1){
                if(mi+matrix[rec][j]<close[j]||close[j]==-1)close[j]=mi+matrix[rec][j];
            }
        }
    }
}
int main(){
    memset(close,-1,sizeof(close));//memset??????????????¨0???-1???????????°???????§????
    memset(closest,-1,sizeof(closest));
    memset(matrix,-1,sizeof(matrix));
    int i,j;
    cin>>n;
    for(i=0;i<n;i++){
        int a,b;
        cin>>a>>b;
        for(j=0;j<b;j++){
            int c,d;
            cin>>c>>d;
            matrix[a][c]=d;
        }
    }
    closest[0]=0;
    djst();
    for(i=0;i<n;i++){
        cout<<i<<" "<<closest[i]<<endl;
    }
    return 0;
}

C++: #include <iostream>
#include <algorithm>
#define N 100
#define INF (1<<30)
using namespace std;

int n, M[N][N], d[N], color[N] = {0};

void Dijk(int s) {
	int min;
	for (int i = 0;i < n;i++) d[i] = INF;
	d[s] = 0;
	while (true) {
		int u=-1;
	    min = INF;
		for (int i = 0;i < n;i++) {
			if (color[i] == 0 && d[i] < min)
				min = d[i];
			    u = i;
		}

		if (u==-1) break;

		color[u] = 1;

		for (int v = 0;v < n;v++) {
			if (color[v] == 0 && M[u][v] != INF)
				if (d[v] > d[u] + M[u][v]) {
					d[v] = d[u] + M[u][v];
				}
		}
	}

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

}

int main() {

	for (int i = 0;i < N;i++)
		for (int j = 0;j < N;j++) M[i][j] = INF;

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

	Dijk(0);

}

C++: #include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;
const ll inf=99999999999999999;
#define rep(i,t,n) for(int i=t;i<n;i++)
const int maxn=1e2+7;
ll d[maxn][maxn];
int main(){
    int a,n,m,x;ll z;
    scanf("%d",&n);
    rep(i,0,n) rep(j,0,n) d[i][j]=inf;
    rep(i,0,n) d[i][i]=0;
    rep(i,0,n){
        scanf("%d%d",&a,&m);
        rep(j,0,m){
            scanf("%d%lld",&x,&z);
            d[a][x]=min(d[a][x],z);
        }
    }
    if(n==1){
        printf("0 0\n");
        return 0;
    }
    rep(k,0,n) rep(i,0,n) rep(j,0,n) d[i][j]=min(d[i][j],d[i][k]+d[k][j]);
    rep(i,0,n) printf("%d %lld\n",i,d[0][i]);
    return 0;
}

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

typedef long long ll;

struct Edge {
    ll t,w;
};

struct State {
    ll v;
    ll score;
    bool operator < (const State& tgt) const {
	return score > tgt.score;
    }
};

vector<ll> dijkstra(vector<vector<Edge>>& G, const int start) {
    const ll V = G.size();

    vector<ll>res(V,INT_MAX);
    priority_queue<State> q;
    q.push( State{0,0} );
    while( q.size() ) {
	State s = q.top(); q.pop();
	if( res[s.v] != INT_MAX ) continue;
	res[s.v] = s.score;
	for(auto& e : G[s.v]) {
	    if( res[e.t] != INT_MAX ) continue;
	    q.push( State{e.t, s.score + e.w} );
	}
    }
    return res;
}


int main () {

    ll V; cin >> V;
    vector<vector<Edge>> G(V);
    for(int i=0; i<V; i++) {
	ll u,k; cin >> u >> k;
	for(int j=0; j<k; j++) {
	    ll v,w; cin >> v >> w;
	    G[i].push_back( Edge{v,w} );
	}
    }
    vector<ll> res = dijkstra(G,0);
    for(int i=0; i<V; i++) {
	cout << i << " " << res[i] << endl;
    }    
    return 0;
}

C++: #include<iostream>
using namespace std;
static const int MAX = 100;
static const int INFTY = 1000001;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

//Mは隣接行列
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];
            }
        }
        //cout << "u=" << u << endl;
        if(u == -1) break;
        color[u] = BLACK;
        //d[i]にBLACkからiへの最短経路を入れる
        for(int i=0;  i<n; i++){
            if(color[i]!=BLACK) d[i] = min(M[u][i]+d[u], d[i]);
        }
    }
    for(int i=0; i<n; i++){
        cout << i << " " << 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 <cstdio>
#include <set>
#include <algorithm>
#include <cstring>

#define INF 1000000
using namespace std;

struct edge
{
  int to, nxt, w;
};

edge E[500005];
int head[10005], cnt = 0, dist[10005];
void add_edge(int u, int v, int w)
{
  E[cnt].to = v;
  E[cnt].w = w;
  E[cnt].nxt = head[u];
  head[u] = cnt++;
}

void dijkstra(int src)
{
  set <pair <int, int> > setds;
  for (int i = 0; i < 10005; i++)
  {
    dist[i] = INF;
  }
  setds.insert(make_pair(0, src));
  dist[src] = 0;
  while (!setds.empty())
  {
    pair<int, int> tmp = *(setds.begin());
    setds.erase(setds.begin());
    int u = tmp.second;
    for (int e = head[u]; ~e; e = E[e].nxt)
    {
      int v = E[e].to;
      int w = E[e].w;
      if (dist[v] > dist[u] + w)
      {
        if (dist[v] != INF)
        {
          setds.erase(setds.find(make_pair(dist[v], v)));
        }
        dist[v] = dist[u] + w;
        setds.insert(make_pair(dist[v], v));
      }
    }
  }
}

int main()
{
  memset(head, -1, sizeof(head));

  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++)
  {
    int v, deg;
    scanf("%d%d", &v, &deg);
    for (int j = 0; j < deg; j++)
    {
      int to, cost;
      scanf("%d%d", &to, &cost);
      add_edge(v, to, cost);
    }
  }
  dijkstra(0);
  for (int i = 0; i < n; i++)
  {
    printf("%d %d\n", i, dist[i]);
  }
}