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<bits/stdc++.h>
using namespace std;

typedef pair<int, int> P;
const int M = 1000000007;

vector<int> dijkstra(int s, vector<vector<P>> edge) {
    int n = edge.size();
    vector<int> dist(n, M);
    priority_queue<P, vector<P>, greater<P>> q;
    dist[s] = 0;
    q.push(P(0, s));
    while (!q.empty()) {
        P p = q.top();
        q.pop();
        for (auto& e : edge[p.second]) {
            if (dist[e.second] > p.first + e.first) {
                dist[e.second] = p.first + e.first;
                q.push(P(p.first + e.first, e.second));
            }
        }
    }
    return dist;
}


int main() {
    int n;
    cin >> n;
    vector<vector<P>> edge(n);
    for (int i = 0; i < n; ++i) {
        int u, k;
        cin >> u >> k;
        if (i != u) exit(1);
        for (int j = 0; j < k; ++j) {
            int v, c;
            cin >> v >> c;
            edge[i].push_back(P(c, v));
        }
    }
    vector<int> d = dijkstra(0, edge);
    for (int i = 0; i < n; ++i) {
        cout << i << " " << d[i] << "\n";
    }
    return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
using namespace std;
typedef long long ll;
#define INF 2147483647
const int maxn=110;

int n,m[maxn][maxn];
int d[maxn],vis[maxn];
vector <pair<int ,int> > adj[maxn];
void dijkstra(){

    priority_queue<pair<int ,int> > q;
    int d[maxn];
    int color[maxn];
    for(int i=0;i<n;i++){
        d[i]=INF;
        color[i]=0;
    }
    d[0]=0;
    q.push(make_pair(0,0));
    color[0]=1;
    while(!q.empty()){

        pair<int ,int> f=q.top(); q.pop();
        int u=f.second;

        color[u]=2;

        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]==2) continue;
            if(d[v]>d[u]+adj[u][j].second){

                d[v]=d[u]+adj[u][j].second;
                q.push(make_pair(d[v]*(-1),v));
                color[v]=1;
            }
        }

    }
    for(int i=0;i<n;i++)
        cout<<i<<" "<<(d[i]==INF?-1:d[i])<<endl;

}


int main(){

    cin >>n;
    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;
            adj[u].push_back(make_pair(v,c));
        }

    }
    dijkstra();

    return 0;
}

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 (true) {
		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 INFTY = (1 << 21);

int n, m[100][100];

void dijkstra() {
    int minv;
    int d[100], color[100];
    
    for (int i = 0; i < n; i++) {
        d[i] = INFTY;
        color[i] = 0;
    }
    
    d[0] = 0;
    color[0] = 1;
    while(1) {
        minv = INFTY;
        int u = -1;
        for (int i = 0; i < n; i++) {
            if (minv > d[i] && color[i] != 2) {
                u = i;
                minv = d[i];
            }
        }
        if (u == -1) break;
        color[u] = 2;
        for (int v = 0; v < n; v++) {
            if (color[v] != 2 && m[u][v] != INFTY) {
                if (d[v] > d[u] + m[u][v]) {
                    d[v] = d[u] + m[u][v];
                    color[v] = 1;
                } 
            }
        }
    }
    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;
}