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<cstdio>
#include<queue>
#include<utility>
#include<string.h>
#include<vector>
using namespace std;
const int INF = 0x3f3f3f3f;
const int MAXN = 250;
const int MAXM = 1000;
int n, m;
int vis[MAXN];
struct Edge{
	int to, weight, next;
}edge[MAXM];
int head[MAXN];
int cnt;
int d[MAXN];
void addEdge(int from, int to, int weight){
	edge[cnt].to = to;
	edge[cnt].weight = weight;
	edge[cnt].next = head[from];
	head[from] = cnt++;
}
void SPFA(int start){
	queue<int> q;
	memset(d, INF, sizeof(d));
	memset(vis, 0, sizeof(vis));
	q.push(start);
	d[start] = 0;
	while (!q.empty()){
		int from = q.front(); q.pop();
		vis[from] = 0;
		for (int i = head[from]; i != -1; i = edge[i].next){
			int to = edge[i].to;
			int weight = edge[i].weight;
			if (d[to] > d[from] + weight){
				d[to] = d[from] + weight;
				if (!vis[to]){
					vis[to] = 1;
					q.push(to);
				}
			}
		}
	}
}
int main(){
	int from, to, weight, k;
	while (scanf("%d", &n) != EOF){
		m = 0;
		memset(head, -1, sizeof(head));
		for (int i = 0; i < n; i++){
			scanf("%d%d", &from, &k);
			m += k;
			for (int i = 0; i < k; i++){
				scanf("%d%d", &to, &weight);
				addEdge(from, to, weight);
			}
		}
		SPFA(0);
		for (int i = 0; i < n; i++) printf("%d %d\n", i, d[i]);
	}
	return 0;
}

C++: #include <iostream>
// #include <vector>
using namespace std;

const int MAX = 100;
const int INFTY = (1 << 21);
int n;
int M[MAX][MAX];

void dijkstra(int s){
  int color[MAX], d[MAX], p[MAX];
  // vector<int> S;
  for(int i=0;i<n;i++){
    color[i] = 0;
    d[i] = INFTY;
    p[i] = -1;
  }
  d[s] = 0;
  p[s] = -1;
  color[0] = 1;

  while(true){
    int mincost = INFTY;
    int u = -1;
    for(int i=0;i<n;i++){
      if(color[i] != 2 && d[i] < mincost){
        mincost = d[i];
        u = i;
      }
    }

    // if(mincost == INFTY) break;
    if(u == -1) break;
    color[u] = 2;

    // S.push_back(u);
    for(int i=0;i<n;i++){
      if(M[u][i] != -1 && (d[i] > M[u][i] + d[u])){
        d[i] = M[u][i] + d[u];
        color[i] = 1;
        p[i] = u;
      }
    }
  }

  for(int i=0;i<n;i++){
    cout << i << " " << 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;

  for(int i=0;i<n;i++){
    int id, k, v, c;
    cin >> id >> k;
    for(int j=0;j<k;j++){
      cin >> v >> c;
      M[id][v] = c;
    }
  }

  dijkstra(0);
  return 0;
}

C++: #include <cstdio>
#include <queue>
#include <utility>
using namespace std;
static const int INFTY = (1 << 21);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<pair<int, int>> *adj;
int *d;

void dijkstra() {
    priority_queue<pair<int, int>> PQ;
    int d[n], color[n];

    for (int i = 0; i < n; i++) {
        d[i] = INFTY;
        color[i] = WHITE;
    }
    d[0] = 0;
    PQ.push(make_pair(0, 0));

    while (!PQ.empty()) {
        pair<int, int> f = PQ.top();
        PQ.pop();

        int u = f.second;
        color[u] = BLACK;

        if (d[u] < f.first * (-1)) { continue; }

        for (int j = 0; j < adj[u].size(); j++) {
            int v = adj[u][j].first;
            if (color[v] == BLACK) { continue; }
            if (d[u] + adj[u][j].second < d[v]) {
                d[v] = d[u] + adj[u][j].second;
                PQ.push(make_pair(d[v] * (-1), v));
                color[v] = GRAY;
            }
        }
    }
    
    for (int i = 0; i < n; i++) {
        printf("%d %d\n", i, d[i]);
    }
}

int main() {
    scanf("%d", &n);
    adj = new vector<pair<int, int>>[n];
    for (int i = 0; i < n; i++) {
        int u, k;
        scanf("%d %d", &u, &k);
        for (int j = 0; j < k; j++) {
            int v, c;
            scanf("%d %d", &v, &c);
            adj[u].push_back(make_pair(v, c));
        }
    }

    dijkstra();

    return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstring>
#include <queue>
#define INF 9999999
using namespace std;

const int maxn = 10000 + 5;
const int maxm = 500000 + 5;

struct Edge{
	int next;
	int to;
	int value;
	Edge():next(0),to(0),value(INF){}
}G[maxm];

struct Node{
	int to;
	int dist;
	bool operator < (const Node& rhs) const{
		return dist > rhs.dist;
	}
};

int head[maxn],cnt;
int dis[maxn];
bool vis[maxn];

int n;

void Insert(int u,int v,int c){
	G[++cnt].next = head[u];
	G[cnt].to = v;
	G[cnt].value = c;
	head[u] = cnt;
}

void init(){
	memset(dis,INF,sizeof(dis));
	memset(vis,false,sizeof(vis));
}

priority_queue<Node >Q;

void Dijkstar(int s){
	dis[s] = 0;
	Q.push((Node){s,0});
	while(!Q.empty()){
		int u = Q.top().to;Q.pop();
		if(vis[u])continue;
		vis[u] = true;
		for(int e = head[u];e; e = G[e].next){
			int v = G[e].to;
			if(dis[u] + G[e].value < dis[v] && !vis[v]){
				dis[v] = dis[u] + G[e].value;
				Q.push((Node){v,dis[v]});
			}
		}
	}
}

int main(){
	init();
	scanf("%d",&n);
	for(int i = 0;i < n; i++){
		int u,m;
		scanf("%d%d",&u,&m);
		for(int j = 0;j < m; j++){
			int v,c;
			scanf("%d%d",&v,&c);
			Insert(u,v,c);
		}
	}
	Dijkstar(0);
	for(int i = 0;i < n; i++){
		printf("%d %d\n",i,dis[i]);
	}
}