Go: package main

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

//make priority queue
type Item struct {
	id       int
	priority int // this state is priority and distans from start
	index    int
}

type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }

// we want the ascending-priority-queue.
// So we use less than here.
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 = j
	pq[j].index = i
}

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
}

func (pq *PriorityQueue) update(dist int, id int) {
	for _, i := range *pq {
		if i.id == id {
			if i.priority > dist {
				i.priority = dist
			}
		}
	}
}

// the main code
func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())
	return n
}

func dikstra(dist [][]int, n int) []int {
	// preparate priority queue
	inf := 1 << 30
	pq := make(PriorityQueue, n)
	shortests := make([]int, n)
	for i := 0; i < n; i++ {
		pq[i] = &Item{
			id:       i,
			priority: inf,
			index:    i,
		}

		shortests[i] = inf
	}
	pq[0].priority = 0
	shortests[0] = 0
	heap.Init(&pq)

	for pq.Len() > 0 {
		item := heap.Pop(&pq).(*Item)
		shortests[item.id] = item.priority
		for id, d := range dist[item.id] {
			if d != -1 {
				pq.update(item.priority+d, id)
			}
		}
		heap.Init(&pq)
	}
	return shortests
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	// init
	n := nextInt(sc)
	dist := make([][]int, n)
	for i := 0; i < n; i++ {
		dist[i] = make([]int, n)
		for j := 0; j < n; j++ {
			dist[i][j] = -1
		}
	}

	// std Input
	for i := 0; i < n; i++ {
		u := nextInt(sc)
		k := nextInt(sc)
		for j := 0; j < k; j++ {
			v, c := nextInt(sc), nextInt(sc)
			dist[u][v] = c
		}
	}

	shortests := dikstra(dist, n)
	for i, d := range shortests {
		fmt.Printf("%d %d\n", i, d)
	}
}

C++: #include <cstdio>
#include <unordered_map>
#define N 100
#define INF 0x7FFFFFFF

void solve(std::unordered_map<int, int> a[N], const int n){
    std::unordered_map<int, int> result;
    result.insert(std::make_pair(0, 0));
    while(result.size() != n){
        std::pair<int, int> newV;
        newV.first = INF;
        newV.second = INF;
        for(auto &x: result){
            for(auto &y: a[x.first]){
                int w = y.second + x.second;
                if(result.find(y.first) == result.end() && newV.second > w){
                    newV.first = y.first;
                    newV.second = w;
                }
            }
        }
        result.insert(newV);
    }
    for(int i = 0; i < n; ++i){
        std::printf("%d %d\n", i, result.find(i)->second);
    }
}

int main(){
    int n;
    std::scanf("%d", &n);
    std::unordered_map<int, int> a[N];
    for(int i = 0; i < n; ++i){
        int id;
        std::scanf("%d", &id);
        int num;
        std::scanf("%d", &num);
        for(int j = 0; j < num; ++j){
            std::pair<int, int> v;
            std::scanf("%d", &v.first);
            std::scanf("%d", &v.second);
            a[i].insert(v);
        }
    }
    solve(a, n);
    return 0;
}

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

typedef pair<int, int> P;
const int N = 2e5;
const int INF = 1e9;

struct edge{ int to,cost; };
vector< edge > G[N];
int n;

void dikstra(int s){
  priority_queue<P,vector<P>,greater<P>> que;
  int d[N]; //sからの最短距離
  fill(d,d+N,INF);
  d[s] = 0;
  que.push({0,s}); //{頂点,最短距離}

  while( !que.empty() ){
    P p = que.top(); que.pop();
    int v = p.second;
    if(d[v] < p.first) continue;
    for(int i = 0; i < G[v].size(); i++){
      edge e = G[v][i];
      if(d[e.to] > d[v] + e.cost){
        d[e.to] = d[v] + e.cost;
        que.push( {d[e.to],e.to} );
      }
    }
  }

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

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

  cin >> n;
  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;
      G[u].push_back({v,c});
    }
  }
  dikstra(0);

  return 0;
}

C++: #include <iostream>
#include <ios>
#include <vector>
#include <queue>
#include <tuple>
#include <utility>
#include <functional>
using namespace std;

constexpr int INF = 1 << 30;

void read_graph(int n, vector<vector<pair<int, int>>> & Es){
    int u, k, v, c;
    while (n--){
        cin >> u >> k;
        while(k--){
            cin >> v >> c;
            Es[u].push_back(pair<int, int>(v, c));
        }
    }
}

void dijkstra(int start, const vector<vector<pair<int, int>>> & Es, vector<int> & dist){
    priority_queue<pair<int, int>, vector< pair<int, int> >, greater<pair<int, int> > > pq;
    pq.emplace(0, start);
    int d, u, v, c;
    while(!pq.empty()){
        tie(d, u) = pq.top();
        pq.pop();
        if (dist[u] < d) continue;
        dist[u] = d;
        for (auto p : Es[u]){
            tie(v, c) = p;
            if (d + c < dist[v]){
                dist[v] = d + c;
                pq.emplace(d + c, v);
            }
        }
    }
}

int main()
{
    ios::sync_with_stdio(false);
    int n = 0;
    cin >> n;
    vector< vector< pair<int, int> > > Es(n);
    vector<int> dist(n, INF);
    
    read_graph(n, Es);
    dijkstra(0, Es, dist);
    
    for (int i = 0; i != n; ++i){
        cout << i << ' ' << dist[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 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<iostream>
using namespace std;
#define MAX 100
#define INF 1 << 30

int n, A[MAX][MAX], d[MAX];
bool vis[MAX];

void dijkstra(int s){
  for ( int i = 0; i < n; i++){
    d[i] = A[s][i];
    vis[i] = false;
  }
  d[s] = 0;
  vis[s] = true;

  while ( 1 ){
    int minCost = INF;
    for ( int i = 0; i < n; i++){
      if ( !vis[i] && minCost > d[i]){
        minCost = d[i];
        s = i;
      }
    }

    if ( minCost == INF ) break;
    vis[s] = true;

    for ( int i = 0; i < n; i++){
      if ( !vis[i] && d[i] > d[s] + A[s][i]){
        d[i] = d[s] + A[s][i];
      }
    }
  }
}

int main(){
  cin >> n;

  // init
  for ( int i = 0; i < n; i++){
    for ( int j = 0; j < n; j++ ){
      A[i][j] = INF;
    }
  }


  int u, k, v, c;
  for ( int i = 0; i < n; i++){
    cin >> u >> k;
    for ( int j = 0; j < k; j++){
      cin >> v >> c;
      A[u][v] = (c == -1) ? INF : c;
    }
  }

  dijkstra(0);

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

  return 0;
}