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<iostream>
#include<cstdio>
#include<climits>
#include<cstring>
#define INF INT_MAX
using namespace std;
typedef unsigned long long ull;

 
void Init(int f){
  for(int i=0;i<=f+50;i++){
    for(int j=0;j<=f+50;j++)D[i][j] = INF;
  }
}
 
int main(){
int n;
int A[1000][1000];
ull D[1000][1000];
  scanf("%d",&n);
  int u,k,C,V;
  Init(n);
  
  for(int i=0;i<n;i++){
    scanf("%d %d",&u,&k);    
    for(int j=0;j<k;j++){
      scanf("%d %d",&V,&C);
      D[u][V] = C;
      D[V][u] = C;
    }    
  }
  
  for(int i=0;i<n;i++)D[i][i] = 0;
  for(int k=0;k<n;k++)for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j] = min(D[i][j],D[i][k] + D[k][j]);
  for(int i=0;i<n;i++){
    cout << i << " " << D[0][i] << endl;
  }
  
  return 0;
}

C++: #include <iostream>
using namespace std;
#define N 100
#define INFTY (1<<21)
#define WHITE 0
#define GRAY 1
#define BLACK 2

int n, M[N][N];

void dijkstra() {
    int minv;
    int d[N], color[N];

    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;
typedef pair<int, int> P;

struct edge {
    int t, c;
    edge(int t, int c): t(t), c(c) {}
};

const int INF = 1e9;
int n, u, k, v, c;
vector<edge> G[100];
int d[100];

void dijkstra(int s) {
    fill(d, d + n, INF);
    d[s] = 0;

    priority_queue<P, vector<P>, greater<P> > que;
    que.push(P(0, s));
    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.t] <= d[v] + e.c) continue;
            d[e.t] = d[v] + e.c;
            que.push(P(d[e.t], e.t));
        }
    }
}

int main(void) {
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            cin >> v >> c;
            G[u].push_back(edge(v, c));
        }
    }

    dijkstra(0);

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

    return 0;
}

C++: #include<iostream>
using namespace std;
#include<stdio.h>
#include<climits>

#define INFTY INT_MAX

int main()
{
    int n, m, i, j, a, w;
    int* adj[100];
    int* dist[100];
    scanf("%d", &n);
    for(i = 0; i < n; i++){
        scanf("%d %d", &i, &m);
        adj[i] = new int [m + 1];   // adjacensy list.
        dist[i] = new int [m + 1];
        for(j = 0; j < m; j++){
            scanf("%d %d", &a, &m);
            adj[i][j] = a;
            dist[i][j] = w;
        }
        adj[i][m] = -1;
        dist[i][m] = -1;
    }

    int *d, *prev, *Q;
    d = new int [n];
    prev = new int [n];
    Q = new int [n];
    for(i = 0; i < n; i++){ d[i] = INFTY; prev[i] = -1; Q[i] = i; }
    int rest = n;

    int u, v, min;
    d[0] = 0;  // 0 is start.
    while(rest > 0){
        min = INFTY;
        for(i = 0; i < n; i++){
            if(min > d[i] && Q[i] >= 0){ min = d[i]; u = i; }
        }
        Q[u] = -1;
        rest--;
        for(j = 0; adj[u][j] >= 0; j++){
            v = adj[u][j];
            if(d[v] > d[u] + dist[u][j]){
                d[v] = d[u] + dist[u][j];
                prev[v] = u;
            }
        }
    };
    for(i = 0; i < n; i++){ printf("%d %d\n", i, d[i]); }
    for(i = 0; i < n; i++){
        delete adj[i]; delete dist[i]; }
    delete d;
    delete prev;
    delete Q;

    return 0;
}