Go: package main

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

const BIG_COST = 200000

const (
	ST_NOT_YET = iota
	ST_JOINED
)

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	nNodes := scanInt(sc)

	costs := make([][]int, nNodes)
	graph := make([][]int, nNodes)

	states := make([]int, nNodes)
	costSums := make([]int, nNodes)

	for i := 0; i < nNodes; i++ {
		costs[i] = make([]int, nNodes)
		costSums[i] = BIG_COST
	}

	for i := 0; i < nNodes; i++ {
		u := scanInt(sc)
		k := scanInt(sc)
		graph[u] = make([]int, k)
		for d := 0; d < k; d++ {
			v := scanInt(sc)
			graph[u][d] = v
			costs[u][v] = scanInt(sc)
		}
	}

	costSums[0] = 0
	for {
		minCost := BIG_COST
		var u int

		for i, cost := range costSums {
			if states[i] != ST_JOINED && cost < minCost {
				minCost = cost
				u = i
			}
		}

		if minCost == BIG_COST {
			break
		}

		states[u] = ST_JOINED

		for _, v := range graph[u] {
			cost := minCost + costs[u][v]
			if cost < costSums[v] {
				costSums[v] = cost
			}
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i, cost := range costSums {
		fmt.Fprintf(w, "%d %d\n", i, cost)
	}
	w.Flush()
}

func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

C++: #include <iostream>
#include <cstdio> 
using namespace std;
static const int INFTY = (1<<21);
int n, M[100][100];
int color[100],d[100],p[100];

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

    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;
        color[u] = 2;
        for (int v = 0; v < n; v++)
        {
            if (color[v] != 2 && d[u] + M[u][v] < d[v])
            { 
                d[v] = d[u] + M[u][v];
                p[v] = u;
                color[v] = 1;
            }  
        } 
    } 

}

int main()
{
    //freopen("in3.txt","r",stdin);
    int u,k,v,c;
    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++)
    {
        cin>>u>>k;
        for (int j = 0; j < k; j++)
        {
            cin>>v>>c; 
            M[u][v] = c; 
        } 
    } 
    
    dijkstra();

    for (int i = 0; i < n; 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 mincost;
  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)
  {
    mincost = INFTY;
    int u = -1;
    for (int i = 0; i < n; i++)
    {
      if (color[i] != BLACK && d[i] < mincost)
      {
        mincost = d[i];
        u = 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[u] + M[u][v] < d[v])
        {
          d[v] = d[u] + M[u][v];
          color[v] = GRAY;
        }
      }
    }
  }

  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;
    }
  }

  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>

#define SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define llong long long
#define pb(a) push_back(a)
#define INF 999999999

using namespace std;
typedef pair<int, int> P;
typedef pair<llong, llong> LP;
typedef pair<int, P> PP;
typedef pair<llong, LP> LPP;

struct edge { int to, cost; };
typedef pair<int, int> P;

int iy[]={0, 0, 1, -1};
int ix[]={1, -1, 0, 0};

int n, m, a, b;
vector<edge> G[101];
int d[101];

int main(){
	cin >> n;
	for(int i=0;i<n;i++){
		cin >> i;
		cin >> m;
		for(int k=0;k<m;k++){
			cin >> a >> b;
			G[i].push_back({a,b});
		}
	}

	priority_queue<P, vector<P>, greater<P> > que;
	fill(d,d+n,INF);
	d[0] = 0;
	que.push(P(0,0));

	while(!que.empty()){
		P p = que.top(); que.pop();
		int u = p.second;
		if(d[u] < p.first) continue;
		for(int i=0;i<G[u].size();i++){
			edge e = G[u][i];
			if(d[e.to] > d[u]+e.cost){
				d[e.to] =d[u]+e.cost;
				que.push(P(d[e.to],e.to));
			}
		}
	}
	for(int i=0;i<n;i++){
		cout << i << " " << d[i] << endl;
	}
	return 0;
}

C++: #include<bits/stdc++.h>
#include<string>
#include<cctype>
#include<cmath>
#include<queue>
#include<stack> 
#define rep(i,n) for(int i=0;i<(n);i++)
using namespace std;
const int MAX_V=105;
int INF = 100000;
struct edge{int to,cost;};
typedef pair <int,int> P;

int V;
vector <edge> G[MAX_V];
int d[MAX_V];

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));
      }
    }
  }
} 
  
int main(){
  int n;
  cin >> n; V=n;
  rep(i,n){
    int u,k;
    cin >> u >> k;
    rep(j,k){
      int to,cost;
      cin >> to >> cost;
      G[u].push_back(edge{to,cost});
    }
  }     

  dijkstra(0);
  rep(i,n){
    cout << i << ' ' << d[i] << endl;
  }
  return 0;
}

C++: #include <iostream>

const int MAX   = 100;
const int INFTY = (1<<21);
const int WHITE = 0;
const int GRAY  = 1;
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++) {
        std::cout << i << " " << (d[i] == INFTY ? -1 : d[i]) << std::endl;
    }
}

int main() {
    std::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++) {
        std::cin >> u >> k;
        for (int j = 0; j < k; j++) {
            std::cin >> v >> c;
            M[u][v] = c;
        }
    }

    Dijkstra();

    return 0;
}

C++: #include<iostream>
#define INF 200001
int main(){
  int u,k,C,V,A[1000][1000],D[1000][1000],n;
  std::cin >> n;
  for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j] = INF;
  for(int i=0;i<n;i++){  
    std::cin >> u >> k;
    for(int j=0;j<k;j++){
      std::cin >> V >> C;
      D[u][V] = C;
    }  
  }
  for(int i=0;i<n;i++)D[i][i] = 0;
  for(int k=0;k<n;k++)for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j]= std::min(D[i][j],D[i][k] + D[k][j]);
  for(int i=0;i<n;i++)std::cout << i << " " << D[0][i] << std::endl;
  return 0;
}