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>
using namespace std;

#define WHITE 0 
#define GRAY 1
#define BLACK 2
#define INFTY 10000000
int n,color[100],M[100][100],d[100],p[100];
int i,j,u,k,v,c;

void dijkstra(){
  for( i = 0; i < n; i++ ){
    color[i] = WHITE;
    d[i] = INFTY;
  }
  d[0] = 0;
  p[0] = -1;
  int cnt = 0;
  // color[0] = GRAY;
  while(1){
    cnt++;
    //cout << cnt << endl;
    int u = -1;
    int mincost = INFTY;
    for( i = 0; i < n; i++ ){
      if( color[i] != BLACK && d[i] < mincost ){
	mincost = d[i];
	u = i;
      }
    }
    if( u == -1 ) break;
    //    if( mincost == INFTY ) break;
    color[u] = BLACK;

    for( 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];
	  p[v] = u;
	  color[v] = GRAY;
	}
      }
    }
  }

  for( i = 0; i < n; i++ ){
    cout << i << " ";
    if( d[i] == INFTY ) cout << -1;
    else cout << d[i];
    cout << endl;
  }
}

int main(){
 
  cin >> n;

  for( i = 0; i < n; i++ ){
    for( j = 0; j < n; j++ ){
      M[i][j] = INFTY;
    }
  }

  for( i = 0; i < n; i++ ){
    cin >> u >> k;
    for( j = 0; j < k; j++ ){
      cin >> v >> c;
      M[u][v] = c;
    }
  }
  
  dijkstra();

  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;
}

C++: // #define _GLIBCXX_DEBUG // for STL debug (optional)
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <string>
#include <cstring>
#include <deque>
#include <list>
#include <queue>
#include <stack>
#include <vector>
#include <utility>
#include <algorithm>
#include <map>
#include <set>
#include <complex>
#include <cmath>
#include <limits>
#include <cfloat>
#include <climits>
#include <ctime>
#include <cassert>
#include <numeric>
#include <fstream>
#include <functional>
#include <bitset>
using namespace std;
using ll = long long int;
using int64 = long long int;
 
template<typename T> void chmax(T &a, T b) {a = max(a, b);}
template<typename T> void chmin(T &a, T b) {a = min(a, b);}
template<typename T> void chadd(T &a, T b) {a = a + b;}
 
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
const int INF = 1LL << 29;
const ll LONGINF = 1LL << 60;
const ll MOD = 1000000007LL;
 
int main() {
    int N; scanf("%d", &N);
    vector< vector< pair<int, int> > > G(N);
    for(int i=0; i<N; i++) {
        int u, k; scanf("%d%d", &u, &k);
        for(int j=0; j<k; j++) {
            int v, c; scanf("%d%d", &v, &c);
            G[u].emplace_back(v, c);
        }
    }

    vector<int> dist(N, INF), checked(N);
    dist[0] = 0, checked[0] = true;

    int u = 0;
    for(int i=0; i<N; i++) {
        for(auto e : G[u]) {
            int v, c; tie(v, c) = e;
            chmin(dist[v], dist[u] + c);
        }

        int ma = INF, v = 0;
        for(int k=0; k<N; k++) {
            if(checked[k]) continue;
            if(ma > dist[k]) {
                ma = dist[k];
                v = k;
            }
        }
        checked[v] = true;
        swap(u, v);
    }

    for(int i=0; i<N; i++) {
        printf("%d %d\n", i, dist[i]);
    }
    return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <cmath>
#include <cstdio>
using namespace std;
#define MAX 10000000

int b[110];

int solve(int a[110][110], int n){
	b[0] = 0;
	for(int i = 0;i < n;i++){
		for(int j = 1;j < n;j++){
			//if(j == 4)cout << b[4] << i << " " << endl;
			if(a[i][j] != -1)b[j] = min(b[j], a[i][j]+b[i]);
			//if(j == 4)cout << b[4] << i << " " << endl;
		}
	}
	//cout << endl;
	return 0;
}

int main(){
	int a[110][110], n;
	fill((int*)a, (int*)(a+110), -1);
	fill(b, b+110, MAX);
	cin >> n;
	for(int i = 0;i < n;i++){
		int u, k, c, d;
		cin >> u >> k;
		for(int j = 0;j < k;j++){
			cin >> c >> d;
			a[u][c] = d;
		}
	}
	
	for(int i = 0;i < n;i++){
		for(int j = 0;j < n;j++){
			cout << a[i][j] << " ";
		}
		cout << endl;
	}
	
	for(int i = 0;i < 2*n;i++)solve(a, n);
	//solve(a, n);
	for(int i = 0;i < n;i++){
		cout << i << " " << b[i] << endl;
	}
	
	return 0;
}
/*
5
0 3 2 3 3 1 1 2
1 2 0 2 3 4
2 3 0 3 3 1 4 1
3 4 2 1 0 1 1 4 4 3
4 2 2 1 3 3
*/