Go: package main

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

var sc = bufio.NewScanner(os.Stdin)

const T = 10000000

var n int
var A [101][101]int

func nextInt() int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return i
}
func Shortestsearch() {
	var Minimum int
	var d, color [100]int
	var u int

	for i := 0; i < n; i++ {
		d[i] = T
		color[i] = 0
	}

	d[0] = 0
	color[0] = 1

	for {
		Minimum = T
		u = -1
		for i := 0; i < n; i++ {
			if Minimum > d[i] && color[i] != 2 {
				u = i
				Minimum = d[i]
			}
		}
		if u == -1 {
			break
		}
		color[u] = 2
		for j := 0; j < n; j++ {
			if color[j] != 2 && A[u][j] != T {
				if d[j] > d[u]+A[u][j] {
					d[j] = d[u] + A[u][j]
					color[j] = 1
				}
			}
		}
	}
	for i := 0; i < n; i++ {
		fmt.Printf("%d %d\n", i, d[i])
	}
}
func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()

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

C++: #include <bits/stdc++.h>
static const int MAX = 100;
static const int INFTY = 10000000;
int V;
std::vector<std::pair<int, int> > G[MAX];

void dijkstra() {
    std::priority_queue<std::pair<int, int> > pq;
    bool visited[MAX];
    int d[MAX];
    for (int i = 0; i < V; i++) {
        visited[i] = false;
        d[i] = INFTY;
    }
    d[0] = 0;
    pq.push({0, 0}); //dist from target * -1, current node
    visited[0] = true;

    while ( !pq.empty() ) {
        std::pair<int, int> f = pq.top(); pq.pop();
        int current = f.second;
        visited[current] = true;

        if (d[current] < f.first * (-1)) continue;

        for (unsigned long i = 0; i < G[current].size(); i++) {
            int target = G[current][i].first;
            if (visited[target]) continue;
            if (d[target] > d[current] + G[current][i].second) {
                d[target] = d[current] + G[current][i].second;
                pq.push({d[target] * (-1), target});
            }
        }
    }

    for (int i = 0; i < V; i++) {
        std::cout << i << " " << (d[i] == INFTY ? -1 : d[i]) << std::endl;
    }
}



int main()
{
    int source, target, cost, edges;
    std::scanf("%d", &V);
    for (int i = 0; i < V; i++) {
        std::scanf("%d %d", &source, &edges);
        for (int j = 0; j < edges; j++) {
            std::scanf("%d %d", &target, &cost);
            G[source].push_back({target, cost});
        }
    }
    dijkstra();
    return 0;
}

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

#define rep(i,n) for(int i = 0; i < n; i++)
#define Rep(i,n) for(int i = 1; i <= n; i++)
#define sz(x) int(x.size())
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define YesorNo(a) printf(a ? "Yes\n" : "No\n")
#define endl '\n'
#define fi first
#define se second
using ll = long long;
using P = pair<int,int>;
using Pl = pair<ll,ll>;
template<class T> using V = vector<T>;
const int dx[] = {0,1,0,-1,1,1,-1,-1};
const int dy[] = {1,0,-1,0,1,-1,-1,1};
const int inf = (1<<30)-1;
const ll infll = (1LL<<62)-1;
ll ceil(const ll &a, const ll &b){return ((a)+(b)-1)/b;}
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }


void Dijkstra(int s, const vector<vector<P>> &g, vector<int> &dis) {
  priority_queue<P, vector<P>, greater<P>> que; // pair = (cost, v);
  dis[s] = 0;
  que.emplace(0,s);
  while(!que.empty()) {
    P p = que.top(); que.pop();
    int now = p.second;
    if(dis[now] < p.first) continue;
    for(P np : g[now]) {
      int next = np.second;
      if(dis[next] > dis[now] + np.first) {
        dis[next] = dis[now] + np.first;
        que.emplace(dis[next], next);
      }
    }
  }
}


int main(){
    
    int n;
    cin >> n;
    V<V<P>> g(n); // pair = (cost, to);
    rep(i,n) {
        int a, k;
        cin >> a >> k;
        rep(j,k) {
            int b, v;
            cin >> b >> v;
            g[a].emplace_back(v,b);
        }
    }

    V<int> d(n, inf);
    Dijkstra(0,g,d);
    rep(i,n) {
        printf("%d %d\n", i, d[i]);
    }
}

C++: #include <bits/stdc++.h>
#define ll long long int
#define P pair<int,int>
struct edge{int to,cost;};
using namespace std;


class CompareDist
{
public:
    bool operator()(pair<int,int> n1,pair<int,int> n2) {
        return n1.second>n2.second;
    }
};

int V;
vector<vector<edge>> G;
vector<int> d;

void dijkstra(int s){
    priority_queue<P,vector<P>,CompareDist> q;
    //fill(d,d+V,INT_MAX);
    d=vector<int>(V,INT_MAX);
    d[s]=0;
    q.push(P(0,s));
    
    while(!q.empty()){
        P p=q.top();q.pop();
        int v=p.first;
        if(d[v]<p.second)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(P(e.to,d[e.to]));
            }
        }
    }
}
int main(void){
    int n,in,t,c;
    cin>>n;
    V=n;
    G.resize(n);
    d.resize(n);
    for(int i=0;i<n;i++){
        cin>>in;
        int node=in;
        cin>>in;
        for(int j=0;j<in;j++){
            cin>>t>>c;
            G[node].emplace_back((edge){t,c});
        }
        
    }
    dijkstra(0);
    for(int i=0;i<d.size();i++){
        cout<<i<<" "<<d[i]<<endl;
    }
}

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

const static int MAX = 100;
const static int INFTY = (1<<21);
const static int WHITE = 0;
const static int GRAY = 1;
const static 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(true){
    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 <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;
int G[110][110] = {};
int d[110] = {};
int main(){
    int n;
    cin >> n;
    rep(i,n)rep(j,n) G[i][j]=-1;
    rep(i,n){
        int t,m;
        cin >> t >> m;
        rep(j,m){
            int a,b;
            cin >> a >> b;
            G[t][a] = b;
        }
    }

    rep(i,n) d[i] = 900010000;
    d[0] = 0;
    while(true){
        bool update = false;
        rep(i,n){
            rep(j,n){
                if(i==j) continue;
                if(G[i][j] != -1 && d[i] + G[i][j] < d[j]){
                    d[j] = d[i]+G[i][j];
                    update = true;
                }
            }
        }
        if(!update) break;
    }

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

    return 0;
}