Go: package main

import (
	"strconv"
	"fmt"
	"bufio"
	"os"
)
const INF = 1 << 21
var scanner = bufio.NewScanner(os.Stdin)

func nextInt() int {
	scanner.Scan()
	i, e := strconv.Atoi(scanner.Text())
	if e != nil {
		panic(e)
	}
	return i
}


func main() {
	scanner.Split(bufio.ScanWords)
	n := nextInt()
	adj := make([][]int, n)
	for i := range adj {
		adj[i] = make([]int, n)
	}

	for i := 0;i < n; i++ {
		u := nextInt()
		k := nextInt()
		for j := 0; j < k; j++ {
			v := nextInt()
			c := nextInt()
			adj[u][v] = c
		}
	}

	// for i := range adj {
	// 	fmt.Println(adj[i])
	// }

	dist := make([]int, n)
	prev := make([]int, n)
	visited := make([]bool, n)
	dijkstra := func(start int, size int) {
		for i := 0; i < size; i++ {
			dist[i] = INF
			prev[i] = -1
			visited[i] = false
		}
		dist[start] = 0
		for {
			u := -1
			tmp_min := INF
			for i := 0; i < size; i++ {
				if visited[i] == false && dist[i] < tmp_min {
					tmp_min = dist[i]
					u = i
				}
			}
			if u == -1 {
				break
			}
			visited[u] = true
			for i := 0; i < size; i++ {
				if adj[u][i] > 0 {
					w := adj[u][i]
					newlen := dist[u] + w
					if newlen < dist[i] {
						dist[i] = newlen
						prev[i] = u
					}
				}
			}
		}
	}
	dijkstra(0, n)
	for i, cost := range dist {
		fmt.Printf("%d %d\n", i, cost)
	}
}

C++: #include<stdio.h>
main()
{
  int i,j,n,g,count=0;
  int V,A,A1,V1;
  int G[101][101],c[101],INF[101],p[101],mincost;

  for(i = 0; i < 101; i++){
    for(j = 0; j < 101; j++)
      G[i][j] = -1;
  }

  scanf("%d",&n);

  for(i = 0; i < n; i++){
    scanf("%d%d",&V,&A);
    for(j = 0; j < A; j++){
      scanf("%d%d",&V1,&A1);
      G[A][A1] = A1;
    }
  }

  for(i = 0; i < n; i++){
    c[i] = 0;
    p[i] = -1;
    INF[i] = 10000001;
  }

  INF[0] = 0;

  while(1){
    mincost = 10000001;
    for(i = 0; i < n; i++){
      if(c[i] != 2 && INF[i] < mincost){
        mincost = INF[i];
        g = i;
      }
    }
    if(mincost == 10000001)break;

    c[g] = 2;


    for(i = 0; i < n; i++){
      if(G[g][i] != -1 && c[i] != 2 && (G[g][i]+INF[g]) < INF[i]){
        p[i] = g;
        INF[i] = G[g][i] + INF[g];
        c[i] = 1;
      }
    }
  }
INF[0] = 0;

  while(1){
    mincost = 10000001;
    for(i = 0; i < n; i++){
      if(c[i] != 2 && INF[i] < mincost){
        mincost = INF[i];
        g = i;
      }
    }
    if(mincost == 10000001)break;

    c[g] = 2;


    for(i = 0; i < n; i++){
      if(G[g][i] != -1 && c[i] != 2 && (G[g][i]+INF[g]) < INF[i]){
        p[i] = g;
        INF[i] = G[g][i] + INF[g];
        c[i] = 1;
      }
    }
  }
  for(i = 0; i < n; i++)printf("%d %d\n",i,INF[i]);
  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 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();
 
 
}