Go: package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
	"strconv"
)

//make priority queue
type Item struct {
	id       int
	priority int // this state is priority and distans from start
	index    int
}

type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }

// we want the ascending-priority-queue.
// So we use less than here.
func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].priority < pq[j].priority
}

func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = j
	pq[j].index = i
}

func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}

func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	item.index = -1 //for safety
	*pq = old[0 : n-1]
	return item
}

func (pq *PriorityQueue) update(dist int, id int) {
	for _, i := range *pq {
		if i.id == id {
			if i.priority > dist {
				i.priority = dist
			}
		}
	}
}

// the main code
func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())
	return n
}

func dikstra(dist [][]int, n int) []int {
	// preparate priority queue
	inf := 1 << 30
	pq := make(PriorityQueue, n)
	shortests := make([]int, n)
	for i := 0; i < n; i++ {
		pq[i] = &Item{
			id:       i,
			priority: inf,
			index:    i,
		}

		shortests[i] = inf
	}
	pq[0].priority = 0
	shortests[0] = 0
	heap.Init(&pq)

	for pq.Len() > 0 {
		item := heap.Pop(&pq).(*Item)
		shortests[item.id] = item.priority
		for id, d := range dist[item.id] {
			if d != -1 {
				pq.update(item.priority+d, id)
			}
		}
		heap.Init(&pq)
	}
	return shortests
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	// init
	n := nextInt(sc)
	dist := make([][]int, n)
	for i := 0; i < n; i++ {
		dist[i] = make([]int, n)
		for j := 0; j < n; j++ {
			dist[i][j] = -1
		}
	}

	// std Input
	for i := 0; i < n; i++ {
		u := nextInt(sc)
		k := nextInt(sc)
		for j := 0; j < k; j++ {
			v, c := nextInt(sc), nextInt(sc)
			dist[u][v] = c
		}
	}

	shortests := dikstra(dist, n)
	for i, d := range shortests {
		fmt.Printf("%d %d\n", i, d)
	}
}

C++: #include <stdio.h>
#include <stdint.h>
#include <iostream>
#include <fstream>
#include <cassert>
#include <climits>

#include <queue>
#include <memory>
using namespace std;

#define DEBUG (0)

#if DEBUG
#define DPRINTF(...) do { \
    printf("D(L%d) %s: ", __LINE__, __func__); \
    printf(__VA_ARGS__); \
  } while (false)
#else
#define DPRINTF(...)
#endif // DEBUG


const int kMaxVertex = 100;
int g_num_of_vertex;
int g_min_weight[kMaxVertex];


enum State {
    kUnvisited = 0,
    kVisited,
};


struct Edge {
    Edge(int num_vertex)
        : num_vertex_(num_vertex)
    {
        const int size_of_ptr_ = num_vertex_ * num_vertex_;
        weight_ = unique_ptr<int>(new int[size_of_ptr_]);

        for (int i = 0; i < num_vertex_; i++)
            for (int j = 0; j < num_vertex_; j++)
                setWeight(i, j, kInvalidWeight);

        for (int i = 0; i < num_vertex_; i++)
            setWeight(i, i, 0);
    }

    const int kInvalidWeight = INT_MAX;

    bool isConnected(int v0, int v1) const;
    vector<int> getConnectedVertices(int v) const;
    int getWeight(int v0, int v1) const;
    void setWeight(int v0, int v1, int w);

    void printWeight() const;

    int num_vertex_;
    int size_of_ptr_;
    unique_ptr<int> weight_;
};

bool Edge::isConnected(int v0, int v1) const
{
    if (v0 == v1)
        return false;

    if (getWeight(v0, v1) == kInvalidWeight)
        return false;

    return true;
}

vector<int> Edge::getConnectedVertices(int v) const
{
    vector<int> vertices;

    for (int i = 0; i < num_vertex_; i++)
        if (isConnected(v, i))
            vertices.push_back(i);

    return vertices;
}

void Edge::setWeight(int v0, int v1, int w)
{
    assert(0 <= v0 && v0 < num_vertex_);
    assert(0 <= v1 && v1 < num_vertex_);

    int *p = weight_.get() + (v0 * num_vertex_) + v1;
    *p = w;
}

int Edge::getWeight(int v0, int v1) const
{
    int *p = weight_.get() + (v0 * num_vertex_) + v1;
    return *p;
}

void Edge::printWeight() const
{
    DPRINTF("\n");
    for (int i = 0; i < num_vertex_; i++)
    {
        printf("    [%d]", i);
        for (int j = 0; j < num_vertex_; j++)
        {
            printf(" %d", getWeight(i, j));
        }
        cout << endl;
    }
}


struct VtxAndWeight {
    VtxAndWeight(int vtx, int weight)
        : vtx_(vtx)
        , weight_(weight)
    {}

    int vtx_;
    int weight_;
};


void calcShortestPath(int start, const Edge &edge)
{
    DPRINTF("start %d\n", start);
    assert(0 <= start && start < g_num_of_vertex);

    int current = start;
    int weight = 0;

    queue<VtxAndWeight> que;
    que.push(VtxAndWeight(current, weight));

    while (!que.empty())
    {
        VtxAndWeight vw = que.front();
        que.pop();

        int vtx = vw.vtx_;
        int weight = vw.weight_;

        DPRINTF("vtx %d  weight %d\n", vtx, weight);

        if (weight > g_min_weight[vtx])
        {
            continue;
        }
        g_min_weight[vtx] = weight;

        vector<int> connectedVertices = edge.getConnectedVertices(vtx);

        // update weight
        // push to queue as the next vertex to be visited
        for (int next_vtx : connectedVertices)
        {
            int next_weight = weight + edge.getWeight(vtx, next_vtx);
DPRINTF("next_vtx %d  next_weight %d\n", next_vtx, next_weight);
            que.push(VtxAndWeight(next_vtx, next_weight));
        }

    }

}


int main()
{
    cin >> g_num_of_vertex;
    cin.ignore();

    // init
    for (int i = 0; i < g_num_of_vertex; i++)
    {
        g_min_weight[i] = INT_MAX;
    }

    Edge edge(g_num_of_vertex);

    // input
    for (int i = 0; i < g_num_of_vertex; i++)
    {
        int start, degree;
        cin >> start >> degree;

        for (int j = 0; j < degree; j++)
        {
            int dst, weight;
            cin >> dst >> weight;

            edge.setWeight(start, dst, weight);
        }

        cin.ignore();
    }

#if DEBUG
    edge.printWeight();
#endif

    // process
    const int start = 0;
    calcShortestPath(start, edge);

    // output
    for (int i = 0; i < g_num_of_vertex; i++)
        printf("%d %d\n", i, g_min_weight[i]);

    return 0;
}

C++: #include <iostream>
#define WHITE 0
#define GRAY 1
#define BLACK 2
#define MAX_N 101
#define INF 100000000
using namespace std;

int m[MAX_N][MAX_N];
int d[MAX_N];
int color[MAX_N];

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

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

  while (true) {
    int mincost = INF;
    int u = -1;
    for (int i = 0; i < n; i++) {
      if (color[i] != BLACK && d[i] < mincost) {
	mincost = d[i];
	u = i;
      }
    }
    
    if (mincost == INF) break;
    
    color[u] = BLACK;
    for (int v = 0; v < n; v++) {
      if (color[v] != BLACK && m[u][v] != INF) {
	if (d[u] + m[u][v] < d[v]) {
	  d[v] = d[u] + m[u][v];
	  color[v] = GRAY;
	}
      }
    }
  }
}

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

int main() {
  int n;
  cin >> n;

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

  dijkstra(0, n);

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

  return 0;
}