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 <iostream>
#include <vector>

using namespace std;

int d[100];

int main(void)
{
    int n;
    cin >> n;

    int graph[n][n];

    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            graph[i][j] = -1;

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

    for (int i = 0; i < n; i++)
        d[i] = 100000000;
    d[0] = 0;

    vector<int> queue;
    for (int i = 0; i < n; i++)
        queue.push_back(i);

    while (!queue.empty()) {
        int u = queue[0];
        size_t j = 0;
        for (size_t i = 0; i < queue.size(); i++)
            if (d[queue[i]] < d[u]) {
                u = queue[i];
                j = i;
            }
        queue.erase(queue.begin() + j);

        for (int v = 0; v < n; v++)
            if (graph[u][v] > 0)
                if (d[v] > d[u] + graph[u][v])
                    d[v] = d[u] + graph[u][v];
    }

    for (int i = 0; i < n; i++)
        cout << i << " " << d[i] << endl;

    
    return 0;
}

C++: #include<stdio.h>
#include<limits.h>
#define NIL -1
static const int MAX = 1005;
static const int INFTY = (1<<21);

main(){
  int n, i, j, v, c, u, k, minV;
  int M[MAX][MAX], A[MAX], key[MAX], p[MAX];
  /*your code*/

  scanf("%d", &n);
  for ( i = 0; i< n; i++ ){
    for ( j = 0; j < n; j++ ){
      M[i][j] = INFTY;
    }
  }

  for ( i = 0; i < n; i++ ){
    scanf("%d %d", &u, &k);
    for ( j = 0; j < k; j++ ){
      scanf("%d %d", &v, &c);
      M[u][v] = c;
    }
  }

  /*your code*/
  for(i = 0; i < n; i++){
    key[i] = INT_MAX;
    p[i] = NIL;
    A[i] = NIL;
  }
  
  key[0]=0;
  
  while(1){
    
    u = NIL;
    
    minV = INT_MAX;
    
    for(i = 0;  i < n; i++){
      
      if(key[i] < minV && A[i] == NIL){
	
	u = i;
	
	minV = key[i];
	
      }
      
    }  
    if(u == NIL)break;
    
    A[u] = u; 
    
    for(v = 0; v < n; v++){
      if((M[u][v]+key[u]) < key[v] && A[v] == NIL){
	key[v] = (M[u][v]+key[u]);
	p[v] = u;
      }
    }
  }
  
  for ( i = 0; i < n; i++ ){
    printf("%d %d\n", i, (key[i]==INFTY?-1:key[i]));
  }

  return 0;

}

C++: #include <iostream>
using namespace std;
#define MAX 100
#define INFTY (1<<30)
#define rep(i,n) for(int i=0;i<n;i++)
enum{
	white,
	gray,
	black,
};

int n,m[MAX][MAX];

 void dijkstra(){
 	int minv;
 	int d[MAX],color[MAX];
 	rep(i,n){
 		d[i]=INFTY;
 		color[i]=white;
 	}
	d[0]=0;
 	color[0]=gray;
 	while(1){
 		minv=INFTY;
 		int u=-1;
 		rep(i,n){
 			if(minv>d[i]&&color[i]!=black){
 				u=i;
 				minv=d[i];
 			}
 		}
 		if(u==-1)	break;
 		color[u]=black;
 		rep(v,n){
 			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;
 				}
 			}
 		}
 	}
 	rep(i,n){
 		cout<<i<<" ";
 		if(d[i]==INFTY)	cout<<-1<<endl;
 		else	cout<<d[i]<<endl;
 	}
 }

 int main(){
 	cin>>n;
 	rep(i,n){
 		rep(j,n)		m[i][j]=INFTY;
 	}
 	int k,c,u,v;
 	rep(i,n){
 		cin>>u>>k;
 		rep(j,k){
 			cin>>v>>c;
 			m[u][v]=c;
 		}
 	}
 	dijkstra();
 	return 0;
 }

C++: #include<bits/stdc++.h>
using namespace std;
#define M 1000000007
#define ff first.first
#define fs first.second
#define sf second.first
#define ss second.second
typedef pair<int,int> P;
typedef pair<P,P> PP;

int main(void)
{
	int i,j,k,u,n,flg[10001],v,c,sum,ky[10001],t,min,g;
	PP ke[10001];
	scanf("%d",&n);
	sum=0;
	for(i=0;i<n;i++) ky[i]=M,flg[i]=0;
	ky[0]=0;
	for(i=0;i<n;i++){
		scanf("%d%d",&u,&k);
		for(j=sum;j<k+sum;j++){
			scanf("%d%d",&v,&c);
			ke[j].ff=u , ke[j].fs=v , ke[j].sf=c;
		}
		sum+=k;
	}
	sort(ke,ke+sum);
	//for(i=0;i<sum;i++) printf("ke[%d].ff=%d ke[%d].fs=%d ke[%d].sf=%d\n",i,ke[i].ff,i,ke[i].fs,i,ke[i].sf);
	for(i=0;i<sum;i++){
		/*min=M;
		for(j=0;j<sum;j++) if(flg[j]==0&&min>ky[j]) g=j,min=j;
		flg[g]=1;
		if(min==M) break;*/
		for(j=0;j<sum;j++){
			t=ky[ke[j].ff]+ke[j].sf;
			if(ky[ke[j].fs]>t) ky[ke[j].fs]=t;
		}
	}
	for(i=0;i<n;i++) printf("%d %d\n",i,ky[i]);
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
struct cww{cww(){ios::sync_with_stdio(false);cin.tie(0);}}star;
#define P(x) cout << (x) << endl
#define p(x) cout << (x)
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define vv(type, c, m, n, i) vector<vector<type>> c(m, vector<type>(n, i));
#define rep(i,a,n) for(int i=(a), i##_len=(n); i<i##_len; ++i)
#define rrep(i,a,n) for(int i=(a), i##_len=(n); i>i##_len; --i)
#define len(x) ((int)(x).size())
#define mp make_pair
#define eb emplace_back
typedef long long ll;
typedef vector<int> vi;
typedef vector<double> vd;
typedef vector<long long> vll;
typedef vector<string> vs;
typedef vector<bool> vb;
constexpr int MAX = 100;
enum Color { WHITE = 0, GRAY, BLACK };
int n;
vv(int, M, MAX, MAX, INT_MAX);
inline void dijkstra() {
    vi d(MAX, INT_MAX), color(MAX, WHITE);
    d[0] = 0;
    color[0] = GRAY;
    int minv, u;
    while(true) {
        minv = INT_MAX;
        u = -1;
        rep(i, 0, n) {
            if(minv > d[i] && color[i] != BLACK) {
                u = i;
                minv = d[i];
            }
        }
        if(u == -1) break;
        color[u] = BLACK;
        rep(v, 0, n) {
            if(color[v] != BLACK && M[u][v] != INT_MAX && d[v] > d[u] + M[u][v]) {
                d[v] = d[u] + M[u][v];
                color[v] = GRAY;
            }
        }
    }
    rep(i, 0, n) {
        cout << i << " " << d[i] << "\n";
    }
}
int main() {
    cin >> n;
    int u, k, v, c;
    rep(i, 0, n) {
        cin >> u >> k;
        rep(j, 0, k) {
            cin >> v >> c;
            M[u][v] = c;
        }
    }
    dijkstra();
    return 0;
}