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>
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;
        }
       }
     }
  }
    if(u == -1) break;
    color[u] = BLACK;
   for(int v = 0; v < n; v++){
    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,v,c,u;
 for(int i = 0;i < n; i++){
  cin >> u >>c;
  M[u][v] = c;
  }
 }
  dijkstra();
   return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define WHITE 0
#define VISITED 1
#define CANDIDATE 2

int dks(vvi &a, vi &d, vi &s, vi &p) {
  int total = 0, n = (int)a.size();
  while (true) {
    int min_cost = INT_MAX, u;
    rep(i, n) {
      if (s[i] != VISITED && d[i] < min_cost) {
        min_cost = d[i];
        u = i;
      }
    }

    if (min_cost == INT_MAX) break;

    s[u] = VISITED;
    if (p[u] != -1) total += a[p[u]][u];

    rep(v, n) {
      if (s[v] != VISITED && a[u][v] != -1) {
        if (d[u] + a[u][v] < d[v]) {
          d[v] = d[u] + a[u][v];
          p[v] = u;
          s[v] = CANDIDATE;
        }
      }
    }
  }
  
  return total;
}

int main() {
  int n;
  cin >> n;

  vvi g(n, vi(n, -1));
  rep(i, n) {
    int u, k;
    cin >> u >> k;

    rep(j, k) {
      int v, c;
      cin >> v >> c;

      g[u][v] = c;
    }
  }
  
  vi d(n, INT_MAX), s(n, WHITE), p(n, -1);
  d[0] = 0;
  
  dks(g, d, s, p);
  
  rep(i, n) printf("%d %d\n", i, d[i]);
}

C++: #include <iostream>
using namespace std;
static const int MAX = 100;
static const int INFTY = (1<<21);
static const int WHITH = 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] = WHITH;
  }

  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;
static const int N = 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[N][N],d[N];

void dijkstra(int s){
	int color[N],p[N];
	for(int i=0;i<n;i++){
		color[i] = WHITE;
		d[i] = INFTY;
	}
	d[s] = 0;
	p[s] = -1;

	int u;
	while(1){
		int minv = INFTY;
		for(int i=0;i<n;i++){
			if(color[i]!=BLACK&&d[i]!=INFTY){
				if(d[i] < minv){
					minv = d[i];
					u = i;
				}
			}
		}
		if(minv == INFTY)break;
		color[u] = BLACK;
		for(int i=0;i<n;i++){
			if(color[i]!=BLACK&&M[u][i]!=INFTY){
				if(d[u]+M[u][i] < d[i]){
					d[i] = d[u]+M[u][i];
					p[i] = u;
				}
			}
		}
	}
}

int main(){
	cin >> n;
	int e,u,k,c,v;
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			M[i][j] = INFTY;
		}
	}
	for(int i=0;i<n;i++){
		cin >> u >> k;
		for(int j=0;j<k;j++){
			cin >> v >> c;
			M[i][v] = c;
		}
	}
	dijkstra(0);
	for(int i=0;i<n;i++){
		cout << i << " " << d[i] << endl;
	}
	return 0;
}