Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

var infty = 1000000000

type DirectedGraphNodeID int

type DirectedGraphNode struct {
	key         DirectedGraphNodeID
	adjacents   []*DirectedGraphNode
	costs       []int
	distance    int
	predecessor *DirectedGraphNode
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]*DirectedGraphNode, nNodes)
	for i := 0; i < nNodes; i++ {
		node := DirectedGraphNode{}
		node.key = DirectedGraphNodeID(i)
		node.distance = infty
		graph.nodes[i] = &node
	}
	return &graph
}

type DirectedGraph struct {
	nodes []*DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(i, j DirectedGraphNodeID, cost int) {
	g.nodes[i].adjacents = append(g.nodes[i].adjacents, g.nodes[j])
	g.nodes[i].costs = append(g.nodes[i].costs, cost)
}

func (g *DirectedGraph) print() {
	for i := 0; i < len(g.nodes); i++ {
		node := g.nodes[i]
		key := node.key
		strings := []string{strconv.Itoa(int(key)), strconv.Itoa(node.distance)}
		for j := 0; j < len(node.adjacents); j++ {
			nodeJ := fmt.Sprintf("(%v, %v)", node.adjacents[j].key, node.costs[j])
			strings = append(strings, nodeJ)
		}
		fmt.Printf("%v\n", strings)
	}
}

func (g *DirectedGraph) relaxEdge(l, r *DirectedGraphNode, w int) {
	if r.distance > l.distance+w {
		// fmt.Printf("%v -> %v, %v\n", l.key, r.key, l.distance+w)
		r.distance = l.distance + w
		r.predecessor = l
	}
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	graph := newDirectedGraph(nNodes)

	for i := 0; i < nNodes; i++ {
		iNode := DirectedGraphNodeID(nextInt())
		nAdjacent := nextInt()
		for j := 0; j < nAdjacent; j++ {
			jNode := DirectedGraphNodeID(nextInt())
			cost := nextInt()
			graph.setAdjacency(iNode, jNode, cost)
		}
	}

	graph.nodes[0].distance = 0
	for iNode := 0; iNode < nNodes; iNode++ {
		for iLeft := 0; iLeft < len(graph.nodes); iLeft++ {
			nodeLeft := graph.nodes[iLeft]
			for iRight := 0; iRight < len(nodeLeft.adjacents); iRight++ {
				nodeRight := nodeLeft.adjacents[iRight]
				cost := nodeLeft.costs[iRight]
				graph.relaxEdge(nodeLeft, nodeRight, cost)
			}
		}
	}

	// graph.print()

	for iNode := 0; iNode < len(graph.nodes); iNode++ {
		node := graph.nodes[iNode]
		fmt.Println(node.key, node.distance)
	}
}

C++: #include <iostream>
#include <cstdlib>
#include <string>
#include <typeinfo>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <stack>
#include <queue>
using namespace std;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;
static const int INFTY = (1<<20);
static const int MAX =10000;

int n;
vector<pair<int, int> > adj[MAX];

void dijkstra(){
    priority_queue<pair<int, int> > PQ;
    int d[MAX], color[MAX];
    
    for(int i = 0; i < n; i++){
        d[i] = INFTY;
        color[i] = WHITE;
    }
    d[0] = 0;
    PQ.push(make_pair(0,0));
    color[0] = GRAY;
    while(!PQ.empty() ){
        pair<int, int> f = PQ.top();PQ.pop();
        int u = f.second;
        color[u] = BLACK;
        
        if(d[u] < f.first * (-1))continue;
        
        for(int j = 0; j < adj[u].size(); j++){
            int v = adj[u][j].first;
            if(color[v] == BLACK)continue;
            if(d[v] > d[u] + adj[u][j].second){
                d[v] = d[u] + adj[u][j].second;
                PQ.push(make_pair(d[v] * (-1),v));
                color[v] = GRAY;
            }
        }
    }
    for(int i = 0; i < n; i++)cout << i << " " << (d[i] == INFTY ? -1 : d[i]) << endl;
}
int main(){
    int k,c,u,v;
    cin >> n;
    for(int i = 0; i < n; i++){
        cin >> u >> k;
        for(int j = 0; j < k; j++){
            cin >> v >> c;
            adj[u].push_back(make_pair(v,c));
        }
    }
    dijkstra();
    return 0;
}

C++: #include <iostream>
using namespace std;
static const int MAX=100;
static const int INF=1<<21;
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;

int n,A[MAX][MAX];

void dijkstra(){
  int color[MAX],mincost,k,p[MAX],d[MAX];

  for(int i=0;i<n;i++){
    color[i]=WHITE;
    d[i]=INF;
  }
  d[0]=0;
  p[0]=-1;
  color[0]=GRAY;

  while(1){
    mincost=INF;
    for(int i=0;i<n;i++){
      if(color[i]!=BLACK && d[i]<mincost){
	mincost=d[i];
	k=i;
      }
    }
    if(mincost==INF) break;
    color[k]=BLACK;

    for(int i=0;i<n;i++){
      if(color[i]!=BLACK && A[k][i]!=INF){
	if(d[k]+A[k][i]<d[i]){
	  d[i]=d[k]+A[k][i];
	  p[i]=k;
	  color[i]=GRAY;
	}
      }
    }
  }
  for(int i=0;i<n;i++){
    cout<<i<<" "<<(d[i]==INF ? -1:d[i])<<endl;
  }
}


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

  dijkstra();
}

C++: #include <bits/stdc++.h>
using namespace std;
static const int M=10000;
static int INF=(1<<20);
int n;
vector<pair<int,int > > a[M];
void dijkstra(){
	priority_queue<pair<int,int> > Q;
	int col[M];
	int d[M];
	for(int i=0;i<n;i++){
		col[i]=0;
		d[i]=INF;
	}
	d[0]=0;col[0]=1;
	Q.push(make_pair(0,0));
	while(!Q.empty()){
		pair<int,int>f=Q.top();Q.pop();
		int u=f.second;col[u]=2;
		if(d[u]<f.first)continue;
		for(int j=0;j<a[u].size();j++){
			int v=a[u][j].first;
			if(col[v]==2)continue;
			if(d[v]>d[u]+a[u][j].second){
				d[u]=d[u]+a[u][j].second;
				Q.push(make_pair(d[v]*(-1),v));
				col[v]=1;
			}
		}
	}
	for(int i=0;i<n;i++)cout<<i<<' '<<(d[i]==INF?-1:d[i])<<endl;
}
int main() {
	int k,u,v,c;
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>u>>k;
		for(int j=0;j<k;j++){
			cin>>v>>c;
			a[u].push_back(make_pair(v,c));
		}
	}
	dijkstra();
}

C++: #include<iostream>
#include<algorithm>
#include<queue>
#include<utility>
#include<vector>


using namespace std;



int main() {
	int n,tmp1,tmp2,size;
	int cnt_arrived=0;
	pair<int, int> ptmp;
	priority_queue<pair<int, int>,vector<pair<int,int>>,greater<pair<int,int>>> pq;
	cin >> n;
	int** mat = new int* [n];
	vector<pair<int, int>>* list_adjacent = new vector<pair<int, int>>[n];
	int* dist = new int[n];
	for (int i = 0;i < n;i++) {
		cin >> tmp1 >> size;
		for (int j = 0;j < size;j++) {
			cin >> tmp1 >> tmp2;
			list_adjacent[i].push_back(make_pair(tmp1, tmp2));
		}
		dist[i] = -1;
	}
	pq.push(make_pair(0, 0));
	while (cnt_arrived < n) {
		ptmp = pq.top();
		pq.pop();
		if (dist[ptmp.second] == -1) {
			cnt_arrived++;
			dist[ptmp.second] = ptmp.first;
			for (int i = 0;i < list_adjacent[ptmp.second].size();i++) {
				pq.push(make_pair(ptmp.first + list_adjacent[ptmp.second][i].second, list_adjacent[ptmp.second][i].first));
			}
		}
	}
	for (int i = 0;i < n;i++) {
		cout << i << " " << dist[i] << endl;
	}
}