Go: package main

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

const (
	white int = iota
	gray
	black
)

type node struct {
	id     int
	parent int
	edge   []int
	weight []int
	color  int
}

type graph struct {
	nodes    []node
	distance []int
}

var infty = 1 << 32
var null = -1

func constructgraph() *graph {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n := nextInt(sc)

	g := &graph{make([]node, n), make([]int, n)}

	for i := 0; i < n; i++ {
		id := nextInt(sc)
		edges := nextInt(sc)
		n := node{}
		n.id = id
		n.edge = make([]int, edges)
		n.weight = make([]int, edges)
		n.color = white
		for j := 0; j < edges; j++ {
			to := nextInt(sc)
			w := nextInt(sc)
			n.edge[j] = to
			n.weight[j] = w
		}
		g.nodes[id] = n
	}
	return g
}

func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

func (g *graph) preparedijkstra(s int) {
	for i := 0; i < len(g.nodes); i++ {
		g.nodes[i].color = white
		g.nodes[i].parent = null
		g.distance[i] = infty
	}
	g.distance[s] = 0
}

func (g *graph) dijkstra(s int) []int {
	g.preparedijkstra(s)

	for {
		var u int
		mincost := infty
		for i, d := range g.distance {
			if g.nodes[i].color != black && mincost > d {
				mincost = d
				u = i
			}
		}

		if mincost == infty {
			break
		}

		g.nodes[u].color = black

		for i, e := range g.nodes[u].edge {
			if g.nodes[e].color != black {
				if g.distance[e] > g.distance[u]+g.nodes[u].weight[i] {
					g.distance[e] = g.distance[u] + g.nodes[u].weight[i]
					g.nodes[e].parent = u
					g.nodes[e].color = gray
				}
			}
		}
	}
	return g.distance
}

func printShortestPath(d []int) {
	for i, v := range d {
		fmt.Printf("%d %d\n", i, v)
	}
}

func main() {
	g := constructgraph()
	d := g.dijkstra(0)
	printShortestPath(d)
}

C++: #include <bits/stdc++.h>
using namespace std;
long long INF = 1000000000000000;
vector<long long> bellman_ford(vector<vector<pair<int, int>>> &E, int s){
    int V = E.size();
    vector<long long> d(V, INF);
    d[s] = 0;
    while (1){
        bool update = false;
        for (int i = 0; i < V; i++){
            for (int j = 0; j < E[i].size(); j++){
                int c = E[i][j].first;
                int v = E[i][j].second;
                if (d[v] > d[i] + c && d[i] != INF){
                    d[v] = d[i] + c;
                    update = true;
                }
            }
        }
        if (!update){
            break;
        }
    }
    return d;
}
int main(){
    int n;
    cin >> n;
    vector<vector<pair<int, int>>> E(n);
    for (int i = 0; i < n; i++){
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++){
            int v, c;
            cin >> v >> c;
            E[i].push_back(make_pair(c, v));
        }
    }
    vector<long long> d = bellman_ford(E, 0);
    for (int i = 0; i < n; i++){
        cout << i << ' ' << d[i] << endl;
    }
}

C++: #include <bits/stdc++.h>
#define rep(i, n) for(int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;
using P = pair<int, int>;

struct edge {int to, cost;};

int main(void){
    int n;
    cin >> n;
    vector<edge> d[n];
    rep(i, n){
        int u, k;
        cin >> u >> k;
        rep(j, k){
            int v, c;
            cin >> v >> c;
            d[u].push_back({v, c});
        }
    }
    vector<int> v(n);
    fill(v.begin(), v.end(), INT_MAX);
    priority_queue<P,vector<P>, greater<P>> q;
    q.push({0, 0});
    while(!q.empty()){
        P p = q.top(); q.pop();
        int g = p.second;
        if(v[g] < p.first) continue;
        v[g] = p.first;
        for(auto x : d[g]){
            if(v[x.to] > v[g] + x.cost)
                q.push({v[g] + x.cost, x.to});
        }
    }
    rep(i, n) cout << i << ' ' << v[i] << endl;
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

int n;
vector< vector<int> > G;
vector<int> color, d, p;

void Dijsktra() {
  color.resize(n), d.resize(n, 1000000000), p.resize(n, -1);
  d[0] = 0;

  while (true) {
    int min_cost = 1000000000, u;
    for (int i = 0; i < n; i++) if (color[i] != 2 && d[i] < min_cost) min_cost = d[i], u = i;
    if (min_cost == 1000000000) break;
    color[u] = 2;
    for (int v = 0; v < n; v++) {
      if (color[v] != 2 && G[u][v] != -1)
        if (d[u] + G[u][v] < d[v]) d[v] = d[u] + G[u][v], p[v] = u, color[v] = 1;
    }
  }
}

int main() {
  cin >> n;
  G.resize(n, vector<int>(n, -1));
  for (int i = 0; i < n; i++) {
    int u, k;
    cin >> u >> k;
    for (int i = 0; i < k; i++) {
      int v, c;
      cin >> v >> c;
      G[u][v] = c;
    }
  }

  Dijsktra();

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

C++: #include <bits/stdc++.h>
using namespace std;

typedef long long ll;

struct Edge {
    ll t,w;
};

struct State {
    ll v;
    ll score;
    bool operator < (const State& tgt) const {
	return score > tgt.score;
    }
};

vector<ll> dijkstra(vector<vector<Edge>>& G, const int start) {
    const ll V = G.size();

    vector<ll>res(V,INT_MAX);
    priority_queue<State> q;
    q.push( State{0,0} );
    while( q.size() ) {
	State s = q.top(); q.pop();
	if( res[s.v] != INT_MAX ) continue;
	res[s.v] = s.score;
	for(auto& e : G[s.v]) {
	    if( res[e.t] != INT_MAX ) continue;
	    q.push( State{e.t, s.score + e.w} );
	}
    }
    return res;
}


int main () {

    ll V; cin >> V;
    vector<vector<Edge>> G(V);
    for(int i=0; i<V; i++) {
	ll u,k; cin >> u >> k;
	for(int j=0; j<k; j++) {
	    ll v,w; cin >> v >> w;
	    G[i].push_back( Edge{v,w} );
	}
    }
    vector<ll> res = dijkstra(G,0);
    for(int i=0; i<V; i++) {
	cout << V << " " << res[i] << endl;
    }    
    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 (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;
}