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>
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 min;
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(GRAY){
    min=INFTY;
    int u=-1;
    for(int i=0;i<n;i++){
      if(min>d[i] && color[i]!=BLACK){
	u=i;
	min=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++: #define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;

#define int long long
int dx[] = {1, 0, -1, 0, 1, -1, -1, 1};
int dy[] = {0, 1, 0, -1, 1, 1, -1, -1};

const int MAX_V = 100;
const int INF = 1e12;

struct edge {
    int to, cost;
};
typedef pair<int, int> P;

int V;
vector<edge> G[MAX_V];
int d[MAX_V];

//ダイクストラ法を用いて単一始点最短路問題を解く
void dijkstra(int s) {
    priority_queue<P, vector<P>, greater<P> > que;
    fill(d, d + V, INF);
    d[s] = 0;
    que.push(P(0, s));

    while (!que.empty()) {
        P p = que.top();
        que.pop();
        int v = p.second;
        if (d[v] < p.first)
            continue;
        for (int i = 0; i < G[v].size(); i++) {
            edge e = G[v][i];
            if (d[e.to] > d[v] + e.cost) {
                d[e.to] = d[v] + e.cost;
                que.push(P(d[e.to], e.to));
            }
        }
    }
}

signed main() {
    cin >> V;
    for (int i = 0; i < V; i++) {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            int v, c;
            cin >> v >> c;
            G[u].push_back({v, c});
        }
    }
    dijkstra(0);
    for (int i = 0; i < V; i++) {
        cout << i << " " << d[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;
}

C++: #include <bits/stdc++.h>
using namespace std;
 
#define INF (1 << 30)
 
struct edge{
 
  int cost, to;
 
};
 
struct state{
 
  int node, cost;
  bool operator <(const state &b)const{
    return cost > b.cost;
  }
};
 
int n;
int d[10001];
vector<edge> glaph[10001];
priority_queue<state> qu;
 
void sss(){
 
  fill(d,d+10001,INF);
  qu.push((state){0,0});
  d[0] = 0;
 
  while(!qu.empty()){
 
    state info;
    info = qu.top();
    qu.pop();
 
    for(int i = 0; i < (double)glaph[info.node].size(); i++){
      if(d[glaph[info.node][i].to] > glaph[info.node][i].cost + d[info.node]){
      d[glaph[info.node][i].to] = glaph[info.node][i].cost + d[info.node];
      qu.push((state){glaph[info.node][i].to,d[info.node]}); 
      }
    }
  }
 
  for(int i = 0; i < n; i++){
    cout << i << " " << d[i] << endl;
  }
   
 
 
 
}
 
int main(){
 
  cin >> n;
 
  for(int i = 0; i < n; i++){
    int k, v, c, u;
    cin >> u >> k;
    for(int j = 0; j < k; j++){
      cin >> v >> c;
      glaph[u].push_back((edge){c,v});
    }
  }
 
  sss();
 
 
}

C++: #include <iostream>
#include <vector>
#include <utility>
#include <string>
#include <cmath>
#include <algorithm>
#include <string>
#include <iomanip>
#include <cstdio>
#include <queue>

using namespace std;
using ll = long long;
using ull = unsigned long long;

constexpr ll LL_MAX = numeric_limits<ll>::max();
constexpr ull ULL_MAX = numeric_limits<ull>::max();
constexpr ll I_MAX = numeric_limits<int>::max();
constexpr ull UI_MAX = numeric_limits<unsigned int>::max();

#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a-1;i>=b;i--)

auto sumdig(ll num) {
	ll dig, sum;
	sum = 0;
	while (num) {
		dig = num % 10;
		sum = sum + dig;
		num = num / 10;
	}
	return sum;
}



struct edge {
	int from;
	int to;
	int cost=1;
};


auto dijkstra(vector<vector<edge>> &g, int start = 0) {
	vector<int> d(g.size(), I_MAX);
	vector<bool> flag(g.size(), false);
	d[start] = 0;
	priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int,int>>> nodes;//first dist, second edgenum
	nodes.push(pair<int, int>(0, start));


	while (!nodes.empty()) {
		pair<int, int> n = nodes.top();
		int s_node = n.second;
		nodes.pop();
		if (n.first > d[n.second])continue;
		rep(i, 0, g[s_node].size()) {
			int new_dist = d[s_node] + g[s_node][i].cost;
			int n_num = g[s_node][i].to;
			if (new_dist < d[n_num]) {
				nodes.push(make_pair(new_dist, n_num));
				d[n_num] = new_dist;
			}
		}
	}
	return d;
}

int main() {
	int n;
	cin >> n;
	vector<edge> empty;
	vector<vector<edge>> g(n, empty);
	vector<int> ans;
	
	rep(i, 0, n) {
		int temp;
		cin >> temp;//頂点番号はいらん
		cin >> temp;

		rep(j, 0, temp) {
			int tc, tt;
			cin >> tt >> tc;
			edge tn = { i,tt,tc };
			g[i].push_back(tn);
		}
	}

	ans = dijkstra(g, 0);
	
	rep(i, 0, ans.size()) {
		cout << i << " " << ans[i] << endl;
	}

	return 0;
}