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;
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++: //http://www.deqnotes.net/acmicpc/dijkstra/を参照
//単一始点最短経路
//プライオリティーキューでの実装がよくわからない
#include<iostream>
#include<algorithm>
#include<utility>
#include<vector>
//#include<queue>
using namespace std;

struct Node{
  //ノードの情報
  int num;//ノードの番号
  vector<pair<int,int>> edge;//各エッジの接続先のノード番号とコスト

  //ダイクストラ法用のデータ
  bool confirmed;//確定ノードかどうか
  int mincost;//そのノードへの最小コスト(確定かどうかはconfirmedで決まる)
};
/*
 下の不等号のみで十分(min_costは<のみ使っている)
bool operator>(const Node node1,const Node node2){
  return node1.mincost > node2.mincost;
}
*/
bool operator<(const Node node1,const Node node2){
  return node1.mincost < node2.mincost;
}
/*
bool compare_pair(const pair<int,int> x,const pair<int,int> y){
  return x.second < y.second;
}
*/

pair<vector<pair<int,int>>::iterator,vector<pair<int,int>>::iterator> dijkstra1(vector<Node> Nodex){
  //優先度の低いものを取りだす(popで)
  //取り出したものが接続するノードのmincostを取り出す
  vector<pair<int,int>> c;
  while(Nodex.size()!=0){
    vector<Node>::iterator x=min_element(Nodex.begin(),Nodex.end());
    x->confirmed=true;//これいらない気もする
    c.push_back(make_pair(x->num,x->mincost));
    for(auto i=x->edge.begin();i<x->edge.end();i++){
      vector<Node>::iterator k=Nodex.end();
      for(vector<Node>::iterator j=Nodex.begin();j<Nodex.end();j++){
        if(j->num==i->first){
          k=j;
          break;
        }
      }
      //この下、ループの中でできる、kを定義する必要もない
      if(k!=Nodex.end()){
        if(k->mincost==1000000000){
          k->mincost=x->mincost+ i->second;
        }else{
          //1000000000は十分に大きいのでこの下のみを書けば十分
          k->mincost=min(k->mincost,x->mincost+ i->second);
        }
      }
    }
    Nodex.erase(x);
  }
  sort(c.begin(),c.end());
  return make_pair(c.begin(),c.end());
}

int main(){
  int n;
  vector<Node> Nodes;
  int u,k;
  int v,c;
  cin >> n;
  for(int i=0;i<n;i++){
    Node subNode;
    cin >> u >> k;
    subNode.num=u;
    subNode.confirmed=false;
    if(subNode.num==0){
      //始まりのノードを確定済みにする
      subNode.mincost=0;
    }else{
      subNode.mincost=1000000000;
    }//int型の最大値に近い
    for(int j=0;j<k;j++){
      cin >> v >> c;
      subNode.edge.push_back(make_pair(v,c));
    }
    Nodes.push_back(subNode);
  }
  pair<vector<pair<int,int>>::iterator,vector<pair<int,int>>::iterator> d=dijkstra1(Nodes);
  for(vector<pair<int,int>>::iterator i=d.first;i<d.second;i++){
    cout << (*i).first << " " << (*i).second << endl;
    //cout <, i->first << " " << i->second << endl;でも同じ
  }
}

C++: #include<bits/stdc++.h>
#define rep(i, n) for(int i = 0; i < (n); ++i)

using namespace std;
using ll = long long;
using v1 = vector<int>;
using vl = vector<long long>;
using v2 = vector<vector<int>>;
using v3 = vector<vector<char>>;

int n;
int m[101][101];

void daiksutora(){
	int p[101];
	int d[101];
	int color[101];
	rep(i, n){
		d[i] = 1e8;
		color[i] = 0;
	}
	d[0] = 0;
	p[0] = -1;
	while(1){
		int mincost = 1e8;
		int u = -1;
		rep(i, n){
			if(color[i] != -1 && d[i] < mincost){
				mincost = d[i];
				u = i;
			}
		}
		if(u == -1) break;
		color[u] = -1;
		rep(v, n){
			if(color[v] != -1 && m[u][v] != -1){
				if(d[u]+m[u][v] < d[v]){
					d[v] = d[u]+m[u][v];
					color[v] = 1;
					p[v] = u;
				}
			}
		}
	}
	rep(i, n){
		cout << i << " " << d[i] << endl;
	}
}

int main(){
	cin >> n;
	rep(i, n){
		rep(j, n){
			m[i][j] = -1;
		}
	}
	rep(i, n){
		int u, k, v, c;
		cin >> u >> k;
		rep(i, k){
			cin >> v >> c;
			m[u][v] = c;
		}
	}
	daiksutora();
}