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++: //単一始点最短経路
#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++: #include <iostream>
#include <algorithm>

using namespace std;

#define MAX 100
#define INF (1<<29)
#define rep(i,n) for(int i = 0 ; i < n ; i++)

int main(){
  int n;
  int d[MAX][MAX];

  fill(d[0],d[MAX],INF);

  cin >> n;
  rep(i,n){
    int u,k;
    cin >> u >> k;
    rep(j,k){
      int v,c;
      cin >> v >> c;
      d[u][v] = c;
    }
  }

  d[0][0] = 0;
  rep(k,n){
    rep(i,n){
      rep(j,n){
	d[i][j] = min(d[i][j],d[i][k] + d[k][j]);
      }
    }
  }

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

  return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<vector>
#include<queue>
#include<algorithm>
using namespace std;

#define INF 20000000
typedef struct Edge edge;

struct Edge{
  int src,dst,weight;
  Edge(int start,int end,int cost) :
	src(start),dst(end),weight(cost) {}
};

bool operator < (const edge &e,const edge &f){
  return (e.weight != f.weight) ? (e.weight > f.weight) : (e.src != f.src) ? (e.src < f.src) : (e.dst < f.dst);
}

typedef vector<edge> Edges;

vector<int> dijkstra(Edges,int);

int main(int argc,char* argv[]){
  int n,v,k,dst,weight;
  Edges es;
  vector<int> vec;

  cin >> n;
  for(int i = 0;i < n;i++){
	cin>> v >> k;
	vec.push_back(v);
	for(int j = 0;j < k;j++){
	  cin >> dst >> weight;
	  edge e(i,dst,weight);
	  es.push_back(e);
	}
  }

  vector<int> dist = dijkstra(es,n);

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

vector<int> dijkstra(Edges es,int n){
  vector<int> dist(n);
  priority_queue<edge> que;
  Edges l[n];
  dist.assign(n,INF);
  dist[0] = 0;

  for(int i = 0;i < (int)es.size();i++){
	edge e = es[i];
	l[e.src].push_back(e);
  }

  for(int i = 0;i < (int)l[0].size();i++)
	que.push(l[0][i]);

  while(!que.empty()){
	edge e = que.top();
	que.pop();
	if(dist[e.dst] > dist[e.src] + e.weight){
	  dist[e.dst] = dist[e.src] + e.weight;

	  for(int i = 0;i < (int)l[e.dst].size();i++)
		que.push(l[e.dst][i]);
	}
  }

  return dist;
}

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 ( 1 ) {
      min = INFTY; 
      int a = -1;
      for ( int i = 0; i < n; i++ ) {
         if ( min > d[i] && color[i] != BLACK ) {
             a = i;
             min = d[i];
         }
      }

      if ( a == -1 ) break;
      color[a] = BLACK;
      
      for ( int v = 0; v < n; v++ ) {
         if ( color[v] != BLACK && M[a][v] != INFTY ) {
            if ( d[v] > d[a] + M[a][v] ) {
               d[v] = d[a] + M[a][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 < n; j++ ) {
      cin >> v >> c;
      M[u][v] = c;
      }
   }

   dijkstra();

   return 0;
}