Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
type Node struct {
	cost int
	done bool
}

type Edge struct {
	to, cost int
}

const INF = 1 << 60

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	nodes := make([]Node, N)
	for i := 0; i < N; i++ {
		nodes[i].cost = INF
	}
	E := make([][]Edge, N)
	for i := 0; i < N; i++ {
		id, k := sc.nextInt(), sc.nextInt()
		for j := 0; j < k; j++ {
			to, cost := sc.nextInt(), sc.nextInt()
			E[id] = append(E[id], Edge{to, cost})
		}
	}
	nodes[0].cost = 0
	for {
		cur := 0
		minCost := INF
		for i := 0; i < N; i++ {
			n := nodes[i]
			if !n.done && n.cost < minCost {
				cur = i
				minCost = n.cost
			}
		}
		if minCost == INF {
			break
		}
		nodes[cur].done = true
		for i := 0; i < len(E[cur]); i++ {
			to, cost := E[cur][i].to, E[cur][i].cost+nodes[cur].cost
			if !nodes[to].done && cost < nodes[to].cost {
				nodes[to].cost = cost
			}
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i, nodes[i].cost)
	}
	wtr.Flush()
}

C++: #include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#define INF 200001 
using namespace std;
int n;
int A[1000][1000];
int D[1000][1000];
 
void Init(int f){
  for(int i=0;i<f;i++){
    for(int j=0;j<f;j++)D[i][j] = INF;
  } 
}
 
int main(){
  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] = D[j][i] = min(D[i][j],D[i][k] + D[k][j]);

  for(int i=0;i<n;i++){
    printf("%d %d\n",i,D[0][i]);
  }
 
  return 0;
}

C++: //#include "stdc++.h"
#include <iostream>
#include <vector>
#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <queue>
//#include "my_gettime.hpp"
//#include "my_random.hpp"
//#include "my_util.hpp"
//using namespace std;

struct Edge{
	Edge(int f, int s, int w){first = f; second = s; weight = w;};
	int first;
	int second;
	int weight;
};

struct NodeP{
	NodeP(){};
	NodeP(int i, int p, int w){id = i; prev = p; weight = w;}
	int id;
	int prev;
	int weight;
	bool operator<(const NodeP & inRhs) const{ return weight < inRhs.weight; }
	bool operator>(const NodeP & inRhs) const{ return weight > inRhs.weight; }
};

#define INF (1<<30)
class Graph{
public:
	Graph(int numnodes);
	//~Graph();
	void addEdge(Edge a);
	void addEdge_nonDirect(Edge e);
	std::vector<NodeP> dijkstra(int start);
	int numNodes;
	//Edge *adj;
	std::vector < std::vector<Edge> > adj;
};
Graph::Graph(int n){
	numNodes = n;
	//adj = (Edge *)malloc(sizeof(Edge)*n*n);
	adj.resize(n);
}
void Graph::addEdge(Edge e){
	//adj[ e.first * numNodes + e.second ] = e;
	adj[e.first].push_back(e);
}
void Graph::addEdge_nonDirect(Edge e){
	adj[e.first].push_back(e);
	Edge e2 = e;
	e2.first = e.second;
	e2.second = e.first;
	adj[e2.first].push_back(e2);
}
std::vector<NodeP> Graph::dijkstra(int start){
	//using P = pair<int , int>;
	int *cost = (int *)malloc(sizeof(int)*numNodes);
	char *flag = (char *)malloc(sizeof(char)*numNodes);
	for(int i=0;i<numNodes;i++) flag[i] = 0;
	for(int i=0;i<numNodes;i++) cost[i] = INF;
	cost[start]=0;
	std::priority_queue < NodeP ,std::vector<NodeP>, std::greater<NodeP> > Q;
	Q.push(NodeP(start,0, 0));
	std::vector <NodeP> nodeps(numNodes);

	while( !Q.empty() ){
		NodeP node = Q.top();
		Q.pop();
		if( flag[node.id] == 1 ) continue;
		flag[node.id] = 1;
		cost[node.id] = node.weight;

		nodeps[node.id] = node;

		typedef std::vector<Edge>::iterator ITR;
		for( ITR itr = adj[node.id].begin(); itr !=adj[node.id].end(); itr++ ){
			int dis = node.weight + itr->weight;
			if( cost[itr->second] > dis ){
				Q.push(NodeP(itr->second, node.id, dis));
			}
		}

	}

	free(cost);
	free(flag);

	return nodeps;
}

int main(int argc ,char **argv){
	using namespace std;

	int numNodes;
	cin >> numNodes;

	Graph g(numNodes);

	for(int i=0;i<numNodes;i++){
		int nodeid, numedge;
		cin >> nodeid >> numedge;
		for(int j=0;j<numedge;j++){
			int target, weight;
			cin >> target >> weight;
		//	cout<< nodeid<<" "<<target<<" "<<weight<<endl;
			g.addEdge(Edge(nodeid,target,weight));
		}
	}
	vector<NodeP> nodeps = g.dijkstra(0);
	typedef std::vector<NodeP>::iterator ITR;
	for( ITR itr = nodeps.begin(); itr !=nodeps.end(); itr++ ){
		printf("%d %d\n",itr->prev,itr->id/*,itr->weight*/);
	}
	return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;

#define llong long long 
typedef struct data{
	vector<int> way;
	vector<int> waycost;
	int useway;
	int cost;
}data;

data d[101];
bool ok[101];
int sum;
int hownum;

void solve(int N, int before){
	for(int i = 0; i < d[N].way.size(); i++){
		if(d[N].cost + d[N].waycost[i] < d[d[N].way[i] ].cost){
			d[d[N].way[i] ].cost = min(d[d[N].way[i]].cost, d[N].cost + d[N].waycost[i]);
			d[d[N].way[i]].useway = N;
		}
	}
}

int main(){
	fill_n(ok, 101, false);
	int howway;
	int num;
	cin >> hownum;
	for(int i = 0; i < hownum; i++){
		cin >> num;
		cin >> howway;
		for(int j = 0; j < howway; j++){
			int w,c;
			cin >> w >> c;
			d[num].way.push_back(w);
			d[num].waycost.push_back(c);
		}

		if(num == 0) d[num].cost = 0;
		else d[num].cost = 10000000;
	}

	for(int j = 0; j < hownum; j++){
		for(int i = 0; i < hownum; i++){
			solve(i, -1);
		}
	}

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