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 <iostream>
#include <cstdio>
#include <climits>
#include <cmath>
#include <algorithm>
#include <utility>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#define MAX 100
#define INFTY 1<<30 // 2^30
using namespace std;
typedef long long llong;
static const int NIL = -1;
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 == NIL) 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 ll = long long;
using namespace std;

#define INFint 2e9+1

ll gcd(ll a, ll b) { return __gcd(a,b); } //最大公約数
ll lcm(ll a, ll b) { return a/gcd(a,b)*b; } //最大公倍数

int main(){
// start
  struct edge {int to,cost;};
  int N;
  cin>>N;
  vector<vector<edge>> G(N,vector<edge>());
  for(int i(0);i<N;i++){
    int k,u;
    cin>>k>>u;
    for(int j(0);j<u;j++){
      int v,c;
      cin>>v>>c;
      G[k].push_back({v,c});
    }
  }
  vector<int> d(N); //各頂点の最小値を入れる配列
  fill(d.begin(),d.end(),INFint);
  // first: cont, second: node number 
  priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> q;
  int start = 0;
  d[start] = 0;
  q.push({0,start});

  while(!q.empty()){
    pair<int,int> p = q.top();q.pop();                                                  
    int v = p.second;
    if (d[v] < p.first) continue;
    for (int i(0);i<int(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});
      }
    }
  }
// end
  for(int i(0);i<N;i++){
    cout << i <<" " << d[i] << endl;
  }
  return 0;
}

C++: #include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <cmath> 
using namespace std;
typedef long long ll;

const ll INF = 0x3f3f3f3f ;
const int maxn = 105;
ll maps[105][105];

int main(){
	ll n,m;
	ll from,to,len;
	while(scanf("%lld",&n)!=EOF){
		for(ll i=0;i<105;i++){
			for(ll j=0;j<105;j++) {
				if(i==j) maps[i][j]=0;
				else	maps[i][j]=INF;
			}
		}
		int sum=n;
		while(n--){
			ll node,t;
			ll to,len;
			scanf("%lld%lld",&node,&t);
			for(ll i=1;i<=t;i++){
				scanf("%lld%lld",&to,&len);
					if(maps[node][to]>len){
						maps[node][to]=len;
						maps[to][node]=len;
					}	
			}	
		}
		for(ll k=0;k<sum;k++){
			for(ll i=0;i<sum;i++){
				for(ll j=0;j<sum;j++){
					if(maps[i][j]>maps[i][k]+maps[k][j]){
						maps[i][j]=maps[i][k]+maps[k][j];
					}
				}
			}
		}
		for(ll i=0;i<sum;i++)
			printf("%lld %lld\n",i,maps[0][i]);
	}
	return 0;
}

C++: #include<cstdio>
#include<queue>
#include<utility>
#include<string.h>
#include<vector>
using namespace std;
const int INF = 0x3f3f3f3f;
const int MAXN = 250;
const int MAXM = 1000;
int n, m;
int vis[MAXN];
struct Edge{
	int to, weight, next;
}edge[MAXM];
int head[MAXN];
int cnt;
int d[MAXN];
void addEdge(int from, int to, int weight){
	edge[cnt].to = to;
	edge[cnt].weight = weight;
	edge[cnt].next = head[from];
	head[from] = cnt++;
}
void SPFA(int start){
	queue<int> q;
	memset(d, INF, sizeof(d));
	memset(vis, 0, sizeof(vis));
	q.push(start);
	d[start] = 0;
	while (!q.empty()){
		int from = q.front(); q.pop();
		vis[from] = 0;
		for (int i = head[from]; i != -1; i = edge[i].next){
			int to = edge[i].to;
			int weight = edge[i].weight;
			if (d[to] > d[from] + weight){
				d[to] = d[from] + weight;
				if (!vis[to]){
					vis[to] = 1;
					q.push(to);
				}
			}
		}
	}
}
int main(){
	int from, to, weight, k;
	while (scanf("%d", &n) != EOF){
		m = 0;
		memset(head, -1, sizeof(head));
		for (int i = 0; i < n; i++){
			scanf("%d%d", &from, &k);
			m += k;
			for (int i = 0; i < k; i++){
				scanf("%d%d", &to, &weight);
				addEdge(from, to, weight);
			}
		}
		SPFA(0);
		for (int i = 0; i < n; i++) printf("%d %d\n", i, d[i]);
	}
	return 0;
}

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

const int MAX = 100;
const int INFTY = (1 << 21);
int n;
int M[MAX][MAX];

void dijkstra(int s){
  int color[MAX], d[MAX], p[MAX];
  // vector<int> S;
  for(int i=0;i<n;i++){
    color[i] = 0;
    d[i] = INFTY;
    p[i] = -1;
  }
  d[s] = 0;
  p[s] = -1;
  color[0] = 1;

  while(true){
    int mincost = INFTY;
    int u = -1;
    for(int i=0;i<n;i++){
      if(color[i] != 2 && d[i] < mincost){
        mincost = d[i];
        u = i;
      }
    }

    // if(mincost == INFTY) break;
    if(u == -1) break;
    color[u] = 2;

    // S.push_back(u);
    for(int i=0;i<n;i++){
      if(M[u][i] != -1 && (d[i] > M[u][i] + d[u])){
        d[i] = M[u][i] + d[u];
        color[i] = 1;
        p[i] = u;
      }
    }
  }

  for(int i=0;i<n;i++){
    cout << i << " " << 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;

  for(int i=0;i<n;i++){
    int id, k, v, c;
    cin >> id >> k;
    for(int j=0;j<k;j++){
      cin >> v >> c;
      M[id][v] = c;
    }
  }

  dijkstra(0);
  return 0;
}