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<stdio.h>
main()
{
  int i,j,n,g,count=0;
  int V,A,A1,V1;
  int G[101][101],c[101],INF[101],p[101],mincost;

  for(i = 0; i < 101; i++){
    for(j = 0; j < 101; j++)
      G[i][j] = -1;
  }

  scanf("%d",&n);

  for(i = 0; i < n; i++){
    scanf("%d%d",&V,&A);
    for(j = 0; j < A; j++){
      scanf("%d%d",&V1,&A1);
      G[A][A1] = A1;
    }
  }

  for(i = 0; i < n; i++){
    c[i] = 0;
    p[i] = -1;
    INF[i] = 10000001;
  }

  INF[0] = 0;

  while(1){
    mincost = 10000001;
    for(i = 0; i < n; i++){
      if(c[i] != 2 && INF[i] < mincost){
        mincost = INF[i];
        g = i;
      }
    }
    if(mincost == 10000001)break;

    c[g] = 2;


    for(i = 0; i < n; i++){
      if(G[g][i] != -1 && c[i] != 2 && (G[g][i]+INF[g]) < INF[i]){
        p[i] = g;
        INF[i] = G[g][i] + INF[g];
        c[i] = 1;
      }
    }
  }
INF[0] = 0;

  while(1){
    mincost = 10000001;
    for(i = 0; i < n; i++){
      if(c[i] != 2 && INF[i] < mincost){
        mincost = INF[i];
        g = i;
      }
    }
    if(mincost == 10000001)break;

    c[g] = 2;


    for(i = 0; i < n; i++){
      if(G[g][i] != -1 && c[i] != 2 && (G[g][i]+INF[g]) < INF[i]){
        p[i] = g;
        INF[i] = G[g][i] + INF[g];
        c[i] = 1;
      }
    }
  }
  for(i = 0; i < n; i++)printf("%d %d\n",i,INF[i]);
  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 min;
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(GRAY){
    min=INFTY;
    int u=-1;
    for(int i=0;i<n;i++){
      if(min>d[i] && color[i]!=BLACK){
	u=i;
	min=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++: #define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;

#define int long long
int dx[] = {1, 0, -1, 0, 1, -1, -1, 1};
int dy[] = {0, 1, 0, -1, 1, 1, -1, -1};

const int MAX_V = 100;
const int INF = 1e12;

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

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

//ダイクストラ法を用いて単一始点最短路問題を解く
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));
            }
        }
    }
}

signed main() {
    cin >> V;
    for (int i = 0; i < V; i++) {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            int v, c;
            cin >> v >> c;
            G[u].push_back({v, c});
        }
    }
    dijkstra(0);
    for (int i = 0; i < V; 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 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++){
        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;
}