Go: package main

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

func main() {
	r := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(r, &n)
	cs := make([]map[int]int, n) // []v_i -> c_i
	for h := 0; h < n; h++ {
		var u, k int
		fmt.Fscan(r, &u, &k)
		m := make(map[int]int)
		for i := 0; i < k; i++ {
			var v, c int
			fmt.Fscan(r, &v, &c)
			m[v] = c
		}

		cs[u] = m
	}

	q := make(map[int]int)
	q[0] = 0
	visited := make(map[int]struct{})
	out := make([]int, n)

	for len(q) > 0 {
		u := top(q)
		for uu, c := range cs[u] {
			// Consider the connection between u and uu.
			if _, ok := visited[uu]; ok {
				continue
			}
			if d, ok := q[uu]; !ok || d > q[u]+c {
				q[uu] = q[u] + c
			}
		}

		out[u] = q[u]
		delete(q, u)
		visited[u] = struct{}{}
	}

	for u, d := range out {
		fmt.Println(u, d)
	}
}

func top(q map[int]int) int {
	minu := -1
	min := -1
	for u, d := range q {
		if min < 0 || d < min {
			minu = u
			min = d
		}
	}

	return minu
}

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

int n;
const int INF = 1000000;
vector<vector<int> > v, c;
vector<int> w;

void trip(int id, int dp) {
	if (dp > n)
		return;

	for (int j = 0; j < (int)v[id].size(); j++) {
		if (w[v[id][j]] > w[id] + c[id][j]) {
			w[v[id][j]] = w[id] + c[id][j];
			trip(v[id][j], dp + 1);
		}
	}
}

int main()
{
	cin >> n;

	int u, k, v1, c1;
	v.resize(n);
	c.resize(n);
	w.assign(n, INF);

	for (int i = 0; i < n; i++) {
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			cin >> v1 >> c1;
			v[u].push_back(v1);
			c[u].push_back(c1);
		}
	}

	w[0] = 0;
	trip(0, 1);

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

	return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <queue>
#include <vector>

using std::cin;
using std::cout;
using std::cerr;
using std::endl;

/*
 * dijkstra 法 O(Elog(V))
 * グラフ g において, 始点 start から各頂点への最短経路を返す
*/
struct Edge {
public:
  int to, cost;

  Edge() {}
  Edge(int to, int cost) : to(to), cost(cost) {}
};

std::vector<int> dijkstra(std::vector<std::vector<Edge> >& graph, int start) {
  std::vector<int> d(graph.size(), int(1e9));
  // (x, y) ... x : the minimum distance from start to y, y : now vertex 
  std::priority_queue<std::pair<int, int> > que;

  que.push({0, start});
  d[start] = 0;

  while(!que.empty()) {
    auto p = que.top();
    que.pop();

    for (auto e : graph[p.second]) {
      if (d[e.to] <= p.first + e.cost) continue;

      d[e.to] = p.first + e.cost;
      que.push({d[e.to], e.to});
    }
  }

  return d;
}


int main() {
  int n, u, k, v, c;
  std::vector<std::vector<Edge> > g;

  cin >> n;
  g.resize(n);
  for (int i = 0; i < n; ++i) {
    cin >> u >> k;
    for (int j = 0; j < k; ++j) {
      cin >> v >> c;
      g[u].push_back({v, c});
    }
  }

  auto d = dijkstra(g, 0);

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

  return 0;
}

C++: #define _USE_MATH_DEFINES
#include<iostream>
#include<algorithm>
#include<string>
#include<iomanip>
#include<cmath>
#include<vector>
#include<deque>
#include<queue>
#include<map>
#include<set>
#define ll long long
#define str string
#define ld long double
#define vec vector
#define vll vec<ll>
#define rep(i,a,b) for(ll i=a;i<b;i++)
#define rrep(i,b,a) for(ll i=b;i>=a;i--)
#define ALL(a) a.begin(),a.end()
#define rALL(a) a.rbegin(),a.rend()
#define kai "\n"
#define yuque priority_queue
#define ryuque(t) priority_queue<t,vec<t>,greater<t>>
#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define mie min_element
#define mae max_element
#define tos to_string
#define sep setprecision
#define MOD 1000000007ll
using namespace std;
void solve();
int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	cout << fixed;
	solve();
}

//nCk(mod p)
const ll NUM = 2;
ll fac[NUM], finv[NUM], inv[NUM];
void cmodf(ll p = MOD) {
	fac[0] = fac[1] = 1;
	finv[0] = finv[1] = 1;
	inv[1] = 1;
	rep(i, 2, NUM) {
		fac[i] = fac[i - 1] * i%p;
		inv[i] = p - inv[p%i] * (p / i) % p;
		finv[i] = finv[i - 1] * inv[i] % p;
	}
}
ll cmod(ll n, ll k, ll p = MOD) {
	return fac[n] * (finv[k] * finv[n - k] % p) % p;
}

//最大公約数
ll gcd(ll n, ll m) {
	ll k = n % m;
	while (k != 0) { n = m; m = k; k = n % m; }
	return m;
}
ll gcd(vector<ll> a) {
	rep(i, 1, a.size()) {
		ll k = a[i - 1] % a[i];
		while (k != 0) {
			a[i - 1] = a[i];
			a[i] = k;
			k = a[i - 1] % a[i];
		}
	}
	return a.back();
}

//最小公倍数
ll lcm(ll n, ll m) {
	ll t = n * m, k = n % m;
	while (k != 0) { n = m; m = k; k = n % m; }
	return t / m;
}
ll lcm(vector<ll> a) {
	ll n;
	rep(i, 1, a.size()) {
		n = a[i - 1] * a[i];
		ll k = a[i - 1] % a[i];
		while (k != 0) {
			a[i - 1] = a[i];
			a[i] = k;
			k = a[i - 1] % a[i];
		}
		n /= a[i];
		a[i] = n;
	}
	return n;
}

//keyの小さい方から探していった時に初めてvalueがjoken以上になる時のkey（keyが増えたらvalueも増えるか同じになるとき）
ll value(ll key) {
	/*変更*/
	return 0;
}
ll mink(ll lkey, ll rkey/*ここも調べる*/, ll joken) {
	ll mkey;
	while (lkey != rkey) {
		mkey = (lkey + rkey) / 2;
		if (value(mkey) >= joken)rkey = mkey;
		else lkey = mkey + 1;
	}
	return rkey;
}

//ペア配列の整理
struct pea {
	ll f, s;
	bool operator<(const pea &c)const {
		return f != c.f ? f < c.f : s < c.s;
	};
};

//変数定義

//再帰関数

//アルゴリズム
void solve() {
	ll n; cin >> n;
	vec<vll> a(n, vll(n, MOD));
	rep(i, 0, n) {
		ll u, k; cin >> u >> k;
		rep(j, 0, k) {
			ll v, c; cin >> v >> c;
			a[u][v] = c;
		}
	}
	vll ans(n), p;
	ans[0] = 0;
	p.pub(0);
	rep(i, 0, n)a[i][0] = MOD;
	while (p.size() != n) {
		ll m = MOD, jj;
		rep(i, 0, p.size())rep(j, 0, n)if (ans[p[i]] + a[p[i]][j] < m) {
			m = a[p[i]][j] + ans[p[i]];
			jj = j;
		}
		p.pub(jj);
		ans[jj] = m;
		rep(i, 0, n)a[i][jj] = MOD;
	}
	rep(i, 0, n)cout << i << " " << ans[i] << kai;
}

C++: #include<vector>
#include<iostream>
#include<algorithm>
#define MAX_V 100
#define INF 1e9
using namespace std;
int V;
int d[MAX_V];
int cost[MAX_V][MAX_V];
bool used[MAX_V];

void dijkstra(int s)
{
	d[s] = 0;
	while (true)
	{
		int v = -1;
		for (int u = 0; u < V; u++)
		{
			if (!used[u] && (v == -1 || d[u] < d[v]))
			{
				v = u;
			}
		}
		if (v == -1)
		{
			break;
		}
		used[v] = true;

		for (int u = 0; u < V; u++)
		{
			//if (cost[v][u] = INF)
			//{
			//	continue;
			//}
			d[u] = min(d[u], d[v] + cost[v][u]);
		}
	}

}
int main()
{
	cin >> V;
	for (int i = 0; i < MAX_V; i++)
	{
		for (int j = 0; j < MAX_V; j++)
		{
			cost[i][j] = INF;
		}
	}
	for (int i = 0; i < MAX_V;i++)
	{
		d[i] = INF;
		used[i] = false;
	}
	for (int i = 0; i < V; i++)
	{
		int u;
		cin >> u;
		int k;
		cin >> k;
		for (int j = 0; j < k; j++)
		{
			int v_to;
			cin >> v_to;
			int c;
			cin >> c;

			cost[u][v_to] = c;

		}
	}

	dijkstra(0);

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

	return 0;

}