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>
#include <string>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;

struct Node
{
    vector<int> cost;
    vector<int> vertex;

    bool visited = false;
    int minCost = 100000000;
};

int N;
vector<Node> firstNodes(100);

int findNode(const vector<Node>& nodes)
{
    int minCost = 1000000000;
    int index = -1;
    for (int i = 0; i < nodes.size(); i++)
    {
        if(minCost > nodes[i].minCost && !nodes[i].visited)
        {
            minCost = nodes[i].minCost;
            index = i;
        }   
    }
    return index;
}

int main()
{
    cin >> N;
    int u;
    int k;
    int temp;
    for(int i = 0;i < N;i++)
    {
        cin >> u;
        cin >> k;
        for(int i = 0;i < k;i++)
        {
            cin >> temp;
            firstNodes[u].vertex.push_back(temp);
            cin >> temp;
            firstNodes[u].cost.push_back(temp);
        }
    }

    firstNodes[0].minCost = 0;
    
    for(int vi = 0;vi < N;vi++)
    {
        vector<Node> nodes = firstNodes;
        while(nodes[vi].visited != true)
        {
            //find a node that is visited and has minimum cost
            int index = findNode(nodes);

            Node& minNode = nodes[index];
            int vertex;
            int cost;
            minNode.visited = true;
            for (size_t i = 0; i < minNode.vertex.size(); i++)
            {
                vertex = minNode.vertex[i];
                cost = minNode.cost[i];
                nodes[vertex].minCost = min(nodes[vertex].minCost,minNode.minCost + cost);
            }
        }
        cout << vi << " " << nodes[vi].minCost << endl;
    }
}

C++: #include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
#include <utility>
#include <limits.h>

#define DIRECTED true //有向か無向か
#define ull unsigned long long
#define mp(X , Y) make_pair(X , Y)

using namespace std;

bool operator>(const pair<ull,int> a, const pair<ull,int> b){
    return a.first > b.first;
}

class dijkstra{
public:
    int num;
    vector<ull> dist;
    vector<int> prev;

    vector<vector<pair<int,ull>>> side; 

    dijkstra(){
    }

    dijkstra(int n){

        num = n;
        //0オリジンとの混合を避けるため+1する
        for(int i = 0; i < n + 1; i++){
            dist.push_back(ULONG_LONG_MAX);
            prev.push_back(-1);
            vector<pair<int,ull>> v;
            side.push_back(v);
        }
    }

    void reset(){
        dist.clear();
        prev.clear();

        for(int i = 0; i < num + 1; i++){
            dist.push_back(ULONG_LONG_MAX);
            prev.push_back(-1);

        }
    }

    void input(int f, int t,ull d){

        side[f].push_back(mp(t, d));
        if(!DIRECTED) side[t].push_back(mp(f,d));
    }

    void search(int start){
        
        dist[start] = 0;
        prev[start] = 0;

        priority_queue<pair<ull,int>, vector<pair<ull,int>>, greater<pair<ull,int>>> pq;
        pq.push(mp(0,start));

        while(!pq.empty()){
            
            ull d = pq.top().first;
            int s = pq.top().second;

            for(auto itr = side[s].begin(); itr != side[s].end(); itr++){

                ull tmp_d = (*itr).second;
                int to = (*itr).first; 

                if(dist[to] > d + tmp_d){
                    dist[to] = d + tmp_d;
                    prev[to] = s;
                    pq.push(mp(d + tmp_d,to));
                }
            }

            pq.pop();
        }
    }

    ull min_distance(int to){
        return dist[to];
    }

};

int main(){

    int n,u,k;

    cin >> n;

    dijkstra dijk;
    dijk = dijkstra(n);

    for(int i = 0; i < n; i++){
        scanf(" %d %d",&u,&k);
        for(int j = 0; j < k; j++){
            int v;
            ull c;

            scanf(" %d %llu",&v,&c);

            dijk.input(u,v,c);

        }
    }

    dijk.search(0);
    for(int i = 0; i < n; i++){
        cout << i << " " << dijk.min_distance(i) << endl;
    }
}