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 <algorithm>
#include <bitset>
#include <cctype>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
using namespace std;

void dijkstra(vector<vector<pair<int, int>>>& edges, vector<int>& ds, int start) {
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> q;
    q.push(make_pair(0, start));
    while (!q.empty()) {
        int d = q.top().first;
        int u = q.top().second;
        q.pop();
        if (ds[u] >= 0) {
            continue;
        }
        ds[u] = d;
        for (auto p : edges[u]) {
            q.push(make_pair(d + p.second, p.first));
        }
    }
}

int main() {
    int n;
    cin >> n;
    vector<vector<pair<int, int>>> edges(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;
            edges[u].push_back(make_pair(v, c));
        }
    }

    vector<int> ds(n, -1);
    dijkstra(edges, ds, 0);

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

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
const int maxx=1010;
const int infinity=1<<30;
int A[maxx][maxx],d[maxx];
bool flag[maxx];
int n,a,b,c;
	
int main (){
	cin>>n;
	for(int i=0;i<n;i++){
		flag[i]=false;
		d[i]=infinity;
	}
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			A[i][j]=infinity;
		}
	}
	for(int i=0;i<n;i++){
		cin>>a>>b;
		for(int j=0;j<b;j++){
			cin>>c;
			cin>>A[a][c];
		}
	}
	d[0]=0;
	while(1){
		int minv=infinity,minj=-1;
		for(int i=0;i<n;i++){
			if(flag[i]==false && d[i]<minv){
				minv=d[i];
				minj=i;
			}
		}
		if(minv==infinity) break;
		flag[minj]=true;
		for(int i =0;i<n;i++){
			if(A[minj][i]!=infinity && flag[i]==false && d[i]>=d[minj]+A[minj][i]){
					d[i]=d[minj]+A[minj][i];
			}
		}
	}
	for(int i=0;i<n;i++) cout<<i<<" "<<(d[i]==infinity ? -1 : d[i])<<endl;
	
	return 0;

}

C++: #include<iostream>
using namespace std;
const int MAX = 100;
const int INFTY = (1<<21);
const int WHITE = 0;
const int GRAY = 1;
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 <bits/stdc++.h>
using namespace std;
#define MAX 1000000000

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

  int n; cin >> n;
  vector< vector<int> > f(n, vector<int>(n, MAX));
  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;
      f[u][v] = c;
    }
  }

  vector<int> d(n,MAX);
  vector<bool> used(n, false);
  d[0] = 0;
  while(true){
    int t = -1;
    for(int i = 0; i < n; i++){
      if(!used[i] && (t == -1 || d[t] > d[i])) t = i;
    }
    if(t == -1) break;
    used[t] = true;

    for(int i = 0; i < n; i++){
      d[i] = min(d[i], d[t] + f[t][i]);
    }
  }

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