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++: /*
 * Problem Description: Graph II - Single Source Shortest Path I
 * Category: Graph/Dijkstra
 * Author: Khan
 * Date: 22th October, 2017
 */

#include <iostream>

using namespace std;

static const int MAX = 1000;
static const int INF = (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 u, minv;
    int d[MAX], color[MAX];

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

    d[0] = 0;
    color[0] = GRAY;
    while(true)
    {
        minv = INF;
        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] != INF)
            {
                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] == INF ? -1 : d[i]) << endl;
}

int main(int argc, char const *argv[])
{
    //freopen("sample.txt", "r", stdin);
    cin >> n;
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < n; ++j)
            M[i][j] = INF;
    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>
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;
}

color[0] = GRAY;
d[0] = 0;

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>
#define MAX 100100
#define WHITE 0
#define BLACK 1

int main() {
  int n;
  std::cin >> n;
  int d[110];
  int color[110];

  int G[110][110];
  for(int i=0; i<n; ++i) {
    for(int j=0; j<n; ++j) G[i][j] = MAX;
  }

  for(int i=0; i<n; ++i) {
    d[i] = MAX;
    color[i] = WHITE;
  }

  for(int i=0; i<n; ++i) {
    int u, k;
    std::cin >> u >> k;
    for(int j=0; j<k; ++j) {
      int to, w;
      std::cin >> to >> w;
      G[u][to] = w;
    }
  }

  d[0] = 0;

  // colorも変更する?

  while(true) {
    int u;
    int minicost = MAX;

    // d[s]が最小になる点を選ぶ
    for(int i=0; i<n; ++i) {
      if(d[i] < minicost && color[i] != BLACK) {
        minicost = d[i];
        u = i;
      }
    }

    if(minicost == MAX) break;
    color[u] = BLACK;

    for(int v=0; v<n; ++v) {
      if(d[u] + G[u][v] < d[v]) {
        d[v] = d[u] + G[u][v];
        //p[u] = u;
      }
    }
  }

  for(int i=0; i<n; ++i) {
    std::cout << i << " " << d[i] << std::endl;
  }
}

C++: #include <iostream>
#include <algorithm>
#include <iomanip>
#include <cctype>
#define _USE_MATH_DEFINES
#include <math.h>
#include <string>
#include <list>
using namespace std;

int n, m[100][100], d[100], p[100];

string color[100];

void dijkstra(){
  for(int i = 0; i < n; i++){
    color[i] = "white";
    d[i] = 10000000;
  }

  d[0] = 0;
  p[0] = -1;

  while(1){
    int mincost = 10000000, u;

    for(int i = 0; i < n; i++){
      if(color[i] != "black" && d[i] < mincost){
        mincost = d[i];
        u = i;
      }
    }
    if(mincost == 10000000) break;

    color[u] = "black";

    for(int v = 0; v < n; v++){
      if(color[v] != "black" && m[u][v] < 10000000){
        if(d[u] + m[u][v] < d[v]){
          d[v] = d[u] + m[u][v];
          p[v] = u;
          color[v] = "glay";
        }
      }
    }
  }
}


int main(){

  cin >> n;

  for(int i = 0; i < n; i++){
    for(int j = 0; j < n; j++){
      m[i][j] = 10000000;
    }
  }

  for(int i = 0; i < n; i++){
    int id, k, v, c;
    cin >> id >> k;
    for(int j = 0; j < k; j++){
      cin >> v >> c;
      m[id][v] = c;
    }
  }

  dijkstra();



  for(int i = 0; i < n; i++){
    cout << i << " " << d[i] << endl;
  }

  return 0;
}