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++: // -*- mode:c++; coding:utf-8; c-basic-offset:2; -*-
// ALDS1_12_B: Single Source Shortest Path I

#include <algorithm>
#include <cstdio>

using uint = unsigned int;

class Graph {
  const uint n_;
  uint* const g_;
  const uint INFINIT;
  
public:

  Graph(uint n) : n_(n), g_(new uint[(n_*n_)]), INFINIT(100000*(n_-1)+1) {
    std::fill_n(g_, (n_*n_), INFINIT);
  }

  ~Graph() { delete[] g_; }
  
  uint* operator [](uint i) const { return g_+(n_*i); }

  void dijkstra(uint* dist)
  {
    std::fill_n(dist, n_, INFINIT);
    bool visited[n_];
    std::fill_n(visited, n_, false);
    auto i = 0u; // 0-start
    visited[i] = true;
    dist[i] = 0u;
    for (auto n = 0u; n < n_-1; ++n) {
      auto cur_min = INFINIT;
      auto es = (*this)[i];
      auto base_dist = dist[i];
      for (auto j = 0u; j < n_; ++j) {
        if (visited[j]) continue;
        dist[j] = std::min(dist[j], base_dist+es[j]);
        if (cur_min > dist[j]) {
          cur_min = dist[j];
          i = j;
        }
      }
      visited[i] = true;
      dist[i] = cur_min;
    }
  }
};

int main()
{
  uint n;
  std::scanf("%u", &n);

  Graph g(n);

  uint u, k, c, v;
  for (auto i = 0u; i < n; ++i) {
    std::scanf("%u %u", &u, &k);
    for (auto j = 0u; j < k; ++j) {
      std::scanf("%u %u", &c, &v);
      g[u][c] = v;
    }
  }

  uint dist[n];
  g.dijkstra(dist);
  for (auto i = 0u; i < n; ++i) {
    std::printf("%u %u\n", i, dist[i]);
  }
}

// eof

C++: #include <iostream>
#include <cstdio>
#include <string>
#include <list>
#include <stack>
#include <queue>
#include <algorithm>
#include <utility>
#include <vector>
#include <map>
#include <bitset>

using namespace std;

int main()
{
	int N;
	cin>>N;
	
	vector<vector<int> > cost(N,vector<int>(N,100001));
	cost[0][0]=0;
	pair<int,int> ddata;
	for(int i=0;i<N;i++){
		int u,k;
		cin>>u>>k;
		for(int j=0;j<k;j++){
			cin>>ddata.first>>ddata.second;
			cost[u][ddata.first]=ddata.second;
		}
	}
	//
	
	vector<int> maxcost(N,100001);
	
	priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>> > que;
	
	que.push(pair<int,int>(0,0));
	
	while(!que.empty()){
		int n=que.top().second;
		if(que.top().first<maxcost[n]){
			maxcost[n]=que.top().first;
		}
		for(int j=1;j<N;j++){
			if(que.top().first+cost[n][j]<maxcost[j]){
				maxcost[j]=que.top().first+cost[n][j];
				ddata.first=que.top().first+cost[n][j];
				ddata.second=j;
				que.push(ddata);
			}
		}
		que.pop();
	}
	
	for(int i=0;i<N;i++){
		cout<<i<<' '<<maxcost[i]<<endl;
	}
	return 0;
}

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

const int MAX=105;
int state[MAX],N,D[MAX];
vector<pair<int,int>> S[MAX];
priority_queue<pair<int,int>> Q;

void dijkstra(){
    int cnt=1;
    for(int i=0;i<N;i++){
        state[i]=0;
        D[i]=100000000;
    }
    state[0]=1;
    D[0]=0;
    for(int i=0;i<S[0].size();i++){
        Q.push(make_pair(-S[0][i].second,S[0][i].first));
        D[S[0][i].first]=min(D[S[0][i].first],D[0]+S[0][i].second);
    }
    while(1){
        int a=Q.top().second;
            if(state[a]==0){
            Q.pop();
            state[a]=1;
            cnt++;
            for(int i=0;i<S[a].size();i++){
                if(state[S[a][i].first]==0){
                    Q.push(make_pair(-S[a][i].second,S[a][i].first));
                    D[S[a][i].first]=min(D[S[a][i].first],D[a]+S[a][i].second);
                }
            }
        }
        else Q.pop();
        if(cnt==N) break;
    }
    return;
}


int main(){
   cin>>N;
    for(int i=0;i<N;i++){
        int l,a;cin>>l>>a;
        for(int j=0;j<a;j++){
            int b,c;cin>>b>>c;
            S[i].push_back(make_pair(b,c));
        }
    }
    dijkstra();
    for(int i=0;i<N;i++){
        cout<<i<<" "<<D[i]<<endl;
    }
}

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

#define rep(i, a, b) for (int i = (a); i < (int)(b); i++)
#define rrep(i, a, b) for (int i = (a); i >= (int)(b); i--)
#define all(x) (x).begin(), (x).end()
using i32 = int32_t;
using i64 = int64_t;
using f32 = float;
using f64 = double;
using P   = pair<int, int>;

template <class T>
bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    } else {
        return false;
    }
}
template <class T>
bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    } else {
        return false;
    }
}

template <class T>
void dump_vec(const vector<T>& v) {
    auto len = v.size();
    rep(i, 0, len) {
        cout << v[i] << (i == (int)len - 1 ? "\n" : " ");
    }
}

struct FastIO {
    FastIO() {
        cin.tie(0);
        ios::sync_with_stdio(false);
        cout << fixed << setprecision(20);
    }
} FASTIO;

//---------------------------------------------------------------------------------------------------

struct Edge {
    int from, to;
    i64 cost;
    Edge() {}
    Edge(int t, i64 c) : from(-1), to(t), cost(c) {}
    Edge(int f, int t, i64 c) : from(f), to(t), cost(c) {}

    bool operator<(const Edge& r) const {
        return cost < r.cost;
    }
    bool operator>(const Edge& r) const {
        return cost > r.cost;
    }
};

using Vertex = vector<Edge>;
using Graph  = vector<Vertex>;

// 無向
void link(Graph& g, int from, int to, int cost = 1) {
    g[from].push_back(Edge(from, to, cost));
    g[to].push_back(Edge(to, from, cost));
    return;
}

// 有向
void connect(Graph& g, int from, int to, int cost = 1) {
    g[from].push_back(Edge(from, to, cost));
    return;
}

vector<i64> dijkstra(const Graph& g, int start) {
    const auto inf = numeric_limits<i64>::max();
    vector<i64> dist(g.size(), inf);

    using Pi = pair<i64, int>;
    priority_queue<Pi, vector<Pi>, greater<Pi>> que;
    dist[start] = 0;
    que.push(make_pair(0, 0));
    while (!que.empty()) {
        const auto e    = que.top();
        const auto cost = e.first;
        const auto from = e.second;
        que.pop();
        if (dist[from] < cost) continue;

        for (const auto& e : g[from]) {
            const auto next_cost = e.cost + cost;
            if (chmin(dist[e.to], next_cost)) {
                que.push(make_pair(next_cost, e.to));
            }
        }
    }

    return dist;
}

//---------------------------------------------------------------------------------------------------

signed main() {
    int N;
    cin >> N;
    Graph G(N);
    rep(i, 0, N) {
        int u, k;
        cin >> u >> k;
        rep(j, 0, k) {
            int v, c;
            cin >> v >> c;
            connect(G, u, v, c);
        }
    }
    auto dist = dijkstra(G, 0);
    rep(i, 0, N) {
        cout << i << " " << dist[i] << "\n";
    }
}