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 <cassert>
#include <climits>
#include <algorithm>
#include <iostream>
#include <vector>
#include <list>
#include <string>
#include <queue>
#include <set>

/*
?§????????????¢0??§???????¢????
??????????¢????????????????????????¶????????????????????§???????°????????????§??°?????????????????£???????????????????¢????
while(????????????????????????????????§)
    list = ???????????????.Get????°?????????????????????????
    for(list)
        ?????????????????????
*/

class TVertex;
struct TPath
{
    int Cost;
    TVertex* Target;
    TPath(TVertex* ATarget, int ACost)
     : Target(ATarget), Cost(ACost) {}
    bool operator<(const TPath& Right)const
    {
        if(this->Cost  < 0) return false;
        if(Right.Cost < 0) return true;
        return this->Cost < Right.Cost;
    }
    bool operator>(const TPath& Right)const
    {
        return !((*this) < Right);
    }
};
class TVertex
{
    int FIndex;
    std::priority_queue<TPath, std::vector<TPath>, std::greater<TPath> > FList;
    int FDistance;

public:
    TVertex(int Index)
     : FIndex(Index), FDistance(INT_MAX)
    {}
    void Reserve(int Size)
    {
        // FList.reserve(Size);
    }
    void AddPath(const TPath& Path)
    {
        FList.push(Path);
    }
    void SortPath()
    {
        // std::sort(FList.begin(), FList.end(), Compare);
    }
    void PrintDistance(std::ostream& out)const
    {
        out << FIndex << " " << FDistance << std::endl;
    }
    int GetMinCostPath()const
    {
        if(FList.empty()) return INT_MAX;
        return FList.top().Cost + FDistance;
    }
    void PickupMinCostPath(int MinCost, std::list<TPath>& List)
    {
        while(FList.empty() == false && FList.top().Cost + FDistance == MinCost){
            List.push_back(TPath(FList.top().Target, FList.top().Cost + FDistance));
            FList.pop();
        }
    }
    bool SetDistance(int Distance)
    {
        if(FDistance < Distance) return false;
        FDistance = Distance;
        return true;
    }
};
class TGraph
{
    std::vector<TVertex*> FTable;
    std::set<TVertex*> FShortest;
    void Init(int n)
    {
        assert(n > 0);
        FTable.resize(n);
        for(int i = 0; i < n; ++i){
            FTable[i] = new TVertex(i);
        }
    }
    static bool CompareMinCost(const TVertex* Left, const TVertex* Right)
    {
        return Left->GetMinCostPath() < Right->GetMinCostPath();
    }
    void AddShortest(TVertex* Vertex, int Distance)
    {
        if(Vertex->SetDistance(Distance)){
            FShortest.insert(Vertex);
        }
    }
    std::list<TPath> PickupMinCostPath(int MinCost)
    {
        std::list<TPath> Result;
        for(std::set<TVertex*>::const_iterator It = FShortest.begin();
            It != FShortest.end(); ++It)
        {
            (*It)->PickupMinCostPath(MinCost, Result);
        }
        return Result;
    }
    void SetShortest(const std::list<TPath>& MinCostPathList)
    {
        for(std::list<TPath>::const_iterator It = MinCostPathList.begin();
            It != MinCostPathList.end(); ++It)
        {
            AddShortest(It->Target, It->Cost);
        }
    }
public:
    TGraph(int n)
    {
        Init(n);
    }
    void SetupVertex(std::istream& in)
    {
        int Index;
        in >> Index;
        assert(Index >= 0);
        assert(Index < FTable.size());
        int k;
        in >> k;
        FTable[Index]->Reserve(k);
        for(int i = 0; i < k; ++i){
            int v, c;
            in >> v >> c;
            FTable[Index]->AddPath(TPath(FTable[v], c));
        }
        FTable[Index]->SortPath();
    }
    void SearchShortest()
    {
        FTable[0]->SetDistance(0);
        FShortest.insert(FTable[0]);
        while(FShortest.size() != FTable.size()){
            int MinCost = (*std::min_element(FShortest.begin(), FShortest.end(), CompareMinCost))->GetMinCostPath();
            std::list<TPath> PathList = PickupMinCostPath(MinCost);
            SetShortest(PathList);
        }
    }
    void PrintDistance(std::ostream& out)
    {
        for(int i = 0; i < FTable.size(); ++i){
            FTable[i]->PrintDistance(out);
        }
    }
};

int main()
{
    std::cin.tie(0);
    std::ios::sync_with_stdio(false);
    int n;
    std::cin >> n;
    TGraph Graph(n);
    for(int i = 0; i < n; ++i){
        Graph.SetupVertex(std::cin);
    }
    Graph.SearchShortest();
    Graph.PrintDistance(std::cout);
    return 0;
    
}