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>
#include <queue>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> Pair;
ll inf = 1e10;
int MAX_V;

ll V, E;
vector<Pair> G[100010];
ll d[100010];

void dijkstra(ll s) {
    priority_queue<Pair, vector<Pair>, greater<Pair>> que;
    fill(d, d + V, inf);
    d[s] = 0;
    que.push(Pair(0, s));
    
    while (!que.empty()) {
        Pair p = que.top();
        que.pop();
        
        ll v = p.second;
        if (d[v] < p.first) continue;
        for (int i = 0; i < G[v].size(); i++) {
            Pair e = G[v][i];
            if (d[e.first] > d[v] + e.second) {
                d[e.first] = d[v] + e.second;
                que.push(Pair(d[e.first], e.first));
            }
        }
    }
}

int main() {
    cin >> V;
    for (int i = 0; i < V; i++) {
        int a, et;
        cin >> a >> et;
        for (int j = 0; j < et; j++) {
            int b;
            ll r;
            cin >> b >> r;
            G[a].emplace_back(b, r);
            //G[b].emplace_back(a, r);
        }
    }

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

}

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

#define MAX   100
#define INFTY (1 << 21)
#define WHITE 0
#define GRAY  1
#define BLACK 2

int n, M[MAX][MAX];

void dijkstra() {
  int d[MAX], p[MAX], color[MAX];
  int minv, u;
  for ( int i = 0; i < n; i++ ) {
    d[i] = INFTY;
    p[i] = -1;
    color[i] = WHITE;
  }

  d[0] = 0;
  while ( 1 ) {
    minv = INFTY;
    u = -1;
    for ( int i = 0; i < n; i++ ) {
      if ( minv > d[i] && color[i] != BLACK ) {
        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<cstdio>
#include<climits>
using namespace std;

#define N 130
int n;

int g[N][N];

int weight[N];
bool us[N];

//prim
void prim(){

  int v;
 
  weight[0]=0;
  
  while(true){
    v=-1;
   
    for(int i=0;i<n;i++){
      if(us[i]!=true && (v==-1 ||weight[i]<weight[v]))v=i;
    }

    if(v==-1)break;
    us[v]=true;
 

    for(int i=0;i<n;i++){
      if(weight[i]>(g[v][i]+weight[v])){

        weight[i]=(g[v][i]+weight[v]);
        //      cout <<"fsafa"<<endl;
      }
    }
  }
 
}


int main(){

  int u,k1,c,v;

  for(int i=0;i<N;i++){
    for(int j=0;j<N;j++){
      g[i][j]=9953535;
    }
  }

  //load n
  cin >>n;

  //load data
  for(int i=0;i<n;i++){
    weight[i]=INT_MAX;
    us[i]=false;
    scanf("%d %d",&u,&k1);
    for(int j=0;j<k1;j++){
      scanf("%d %d",&v,&c);
      g[u][v]=c;
      //    cout <<g[i][j]<<" ";
    }
    //    cout <<endl;
  }




  //print
  prim();

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

}

C++: #include <iostream>
#include <cstdlib>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <set>
#include <string>
#include <cmath>
using namespace std;

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define REP(i, k, n) for (int i = (int)(k); i < (int)(n); i++)
#define rrep(i, n) for (int i = (int)(n)-1; i >= 0; i--)
#define rREP(i, k, n) for (int i = (int)(n)-1; i >= k; i--)

#define debug(x) cerr<<#x<<": "<<x<<'\n'

#define fi first
#define se second

#define vi vector<int>
#define pb push_back
#define mp make_pair

#define pcnt __builtin_popcount

typedef long long ll;

const int inf = 100100100;
const int MOD = (int)1e9 + 7;
const double EPS = 1e-9;

struct Edge{
    int to;
    int cost;
}
vector<int> G[110];
int d[110] = {};
int main(){
    int n;
    cin >> n;
    rep(i,n){
        int t,m;
        cin >> t >> m;
        rep(j,m){
            int a,b;
            cin >> a >> b;
            G[t].push_back({a,b})
        }
    }

    rep(i,n) d[i] = 900010000;
    d[0] = 0;
    while(true){
        bool update = false;
        rep(i,n){
            rep(j,G[i].size()){
                if(d[i] + G[i][j].cost < d[G[i][j].to]){
                    d[G[i][j].to] = d[i]+G[i][j].cost;
                    update = true;
                }
            }
        }
        if(!update) break;
    }

    rep(i,n){
        cout << i << " " << d[i] << endl;
    }

    return 0;
}

C++: #include <iostream>
#include <vector>
#define INF 1<<30
#define WHITE 0
#define GRAY 1
#define BLACK 2
int G[101][101];
using namespace std;
int n;

void prim(int *d, int *pi){
    int color[n];
    int u = 0;
    for (int i = 0; i < n; i++){
        d[i] = pi[i] = INF;
        color[i] = WHITE;
    }
    d[0] = 0;
    while (1){
        int mincost = INF;
        for (int i = 0; i < n; i++){
            if (color[i] != BLACK && d[i] < mincost){
                mincost = d[i];
                u = i;
            }
        }
        if (mincost == INF) break;
        color[u] = BLACK;
        for (int v = 0; v < n; v++){
            int w = G[u][v];
            if (w == -1) continue;
            else if (color[v] != BLACK && d[u]+w < d[v]){
                pi[v] = u;
                d[v] = d[u] + w;
            }
        }
    }
}

int main(int argc, char* argv[]) {
    cin >> n;
    int d[n], pi[n], sum = 0;
    int u, k, v, c;

    //initialize
    for (int i = 0; i < n; i++){
        for (int j = 0; j < n; j++){
            G[i][j] = -1;
        }
    }
    //input
    for (int i = 0; i < n; i++){
        cin >> u >> k;
        for (int j = 0; j < k; j++){
            cin >> v >> c;
            G[u][v] = c;
        }
    }
    prim(d, pi);
    for (int i = 0; i < n; i++){
        cout << i << " " << d[i] << endl;
    }
    return 0;
}