Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)

	g := makeGraph(n)
	for i := 0; i < n; i++ {
		u := getNextInt(scanner)
		k := getNextInt(scanner)
		for ii := 0; ii < k; ii++ {
			v := getNextInt(scanner)
			c := getNextInt(scanner)
			g[u][v] = c
		}
	}

	ans := make([]int, n)
	im := make(IntMap, 1)
	im.increment(0)
	for len(im) < n {
		min := 1 << 30
		x := -1
		for u := range im {
			for v := 0; v < n; v++ {
				if im.get(v) != 0 {
					continue
				}
				if min > ans[u]+g[u][v] {
					min = ans[u] + g[u][v]
					x = v
				}
			}
		}
		im.increment(x)
		ans[x] = min
	}

	for i := 0; i < n; i++ {
		fmt.Fprintln(writer, fmt.Sprintf("%d %d", i, ans[i]))
	}
	writer.Flush()
}

func makeGraph(n int) [][]int {
	g := make([][]int, n)
	for i := 0; i < n; i++ {
		g[i] = make([]int, n)
		for ii := 0; ii < n; ii++ {
			g[i][ii] = 1 << 30
		}
	}

	return g
}

// IntMap ...
type IntMap map[int]int

func (m IntMap) get(key int) int {
	if _, ok := m[key]; ok {
		return m[key]
	}
	return 0
}
func (m IntMap) increment(key int) {
	if _, ok := m[key]; ok == false {
		m[key] = 0
	}
	m[key]++
}

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

#define ll long long
#define vvi vector<vector<int>>
#define vec vector
#define pq priority_queue
#define all(v) (v).begin(), (v).end()
#define uniqueV(x) sort(x.begin(), x.end()); x.erase(unique(x.begin(), x.end()), x.end());
#define rep(i, n) for (int (i) = (0); (i) < (n); ++(i))
#define repp(i, m, n) for (int (i) = (m); (i) < (n); ++(i))
#define debug(x) cerr << #x << ": " << x << endl;
#define debug2(x, y) cerr<<"("<<#x<<", "<<#y<<") = "<<"("<<x<<", "<<y<<")"<<endl;
#define debug3(x, y, z) cerr<<"("<<#x<<", "<<#y<<", "<<#z<<") = "<<"("<<x<<", "<<y<<", "<<z<<")"<<endl;
#define debugB(x, y) cerr<<#x<<": "<<bitset<y>(x) << endl;
#define line() cerr << "---------------" << endl;

const int dx[] = {1, -1, 0, 0};
const int dy[] = {0, 0, -1, 1};
const double PI = 3.14159265358979323846;

template<typename T>
void printA(vector<T> &printArray, char between = ' ') {
   int paSize = printArray.size();
   for (int i = 0; i < paSize; i++) { cerr << printArray[i] << between;}
   if (between != '\n') {cerr << endl;}
}

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

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

const int INF = 1e8;
int n;
vec<vec<edge>> G;
int d[111];

void dijkstra(int s) {
   priority_queue<P, vec<P>, greater<P>> Q;
   fill(d, d + n, INF);
   d[s] = 0;
   Q.push({0, s});

   while (Q.size()) {
      P p = Q.top(); Q.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;
            Q.push({d[e.to], e.to});
         }
      }
   }
}

int main() {
   cin >> n;
   G = vec<vec<edge>>(n);
   rep (i, n) {
      int u, k;
      cin >> u >> k;
      rep (j, k) {
         int v, c;
         cin >> v >> c;
         G[u].push_back({v, c});
      }
   }

   dijkstra(0);

   rep (i, n) {
      printf("%d %d\n", i, d[i]);
   }

   return 0;
}

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

const int inf = 1<<29;
int n;
vector<pair<int, int>> G[110];
vector<int> d(110, inf);

void dijkstra(int s){
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> qu;
    d[s] = 0;
    qu.push(make_pair(0, s));

    while(!qu.empty()){
        pair<int, int> p = qu.top(); qu.pop();
        if(d[p.second] < p.first) continue;
        for(auto e:G[p.second]){
            if(d[e.second] > p.first+e.first){
                d[e.second] = p.first+e.first;
                qu.push(make_pair(d[e.second], e.second));
            }
        }
    }
}

int main(){
    cin >> n;
    for(int i=0; i<n; ++i){
        int u, k; cin >> u >> k;
        for(int j=0; j<k; ++j){
            int v, w; cin >> v >> w;
            G[u].push_back(make_pair(w, v));
        }
    }

    dijkstra(0);
    for(int i=0; i<n; ++i){
        cout << i << ' ' << d[i] << '\n';
    }

    return 0;

}

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

using WNode = std::pair<uint32_t, uint32_t>;
using WGraph = std::vector<std::vector<WNode>>;

int main() {
  uint32_t N = 0;
  std::cin >> N;
  WGraph G(N);
  for (size_t i = 0; i < N; i++) {
    uint32_t K = 0;
    std::cin >> i >> K;
    for (size_t j = 0; j < K; j++) {
      uint32_t node = 0, cost = 0;
      std::cin >> node >> cost;
      G[i].push_back({node, cost});
    }
  }

  const uint32_t start = 0;
  std::vector<uint32_t> min_cost(N, -1);
  min_cost[start] = 0;
  std::vector<uint32_t> prev_node(N, -1);
  prev_node[start] = start;
  std::vector<bool> visit(N, false);
  for (size_t i = 0; i < N; i++) {
    uint32_t current = 0, min = -1;
    for (size_t j = 0; j < N; j++) {
      if (visit[j] || min_cost[j] >= min) continue;
      min = min_cost[j];
      current = j;
    }
    visit[current] = true;

    for (auto &&g : G[current]) {
      if (min_cost[g.first] <= g.second + min_cost[current]) continue;
      min_cost[g.first] = g.second + min_cost[current];
      prev_node[g.first] = current;
    }
  }

  for (size_t i = 0; i < N; i++) {
    std::cout << i << " " << min_cost[i] << std::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<iostream>
#include<vector>
#include<algorithm>
#define MAX_V 100
#define INF 1e9
using namespace std;
int cost[MAX_V][MAX_V];
int d[MAX_V];
bool used[MAX_V];
int V;
void dijkstra(int s) {
	for (int i = 0; i < V; i++) {
		d[i] = INF;
		used[i] = false;
	}
	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;
			}
		}
		//全ての頂点が到達済み
		if (v == -1) {
			break;
		}
		//集合に新たに頂点を追加
		used[v] = true;
		for (int u = 0; u < V; u++) {
			if (cost[v][u] != -1) {
				d[u] = min(d[u], d[v] + cost[v][u]);
			}
		}
	}
}

int main() {
	for (int i = 0; i < MAX_V; i++) {
		for (int j = 0; j < MAX_V; j++) {
			cost[i][j] = -1;
		}
	}
	cin >> V;
	for (int i = 0; i < V; i++) {
		int u;
		cin >> u;
		int k;
		cin >> k;
		for (int j = 0; j < k; j++) {
			int v;
			cin >> v;
			int c;
			cin >> c;
			cost[u][v] = c;
		}
	}
	dijkstra(0);

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