Go: package main

import (
	"strconv"
	"fmt"
	"bufio"
	"os"
)
const INF = 1 << 21
var scanner = bufio.NewScanner(os.Stdin)

func nextInt() int {
	scanner.Scan()
	i, e := strconv.Atoi(scanner.Text())
	if e != nil {
		panic(e)
	}
	return i
}


func main() {
	scanner.Split(bufio.ScanWords)
	n := nextInt()
	adj := make([][]int, n)
	for i := range adj {
		adj[i] = make([]int, n)
	}

	for i := 0;i < n; i++ {
		u := nextInt()
		k := nextInt()
		for j := 0; j < k; j++ {
			v := nextInt()
			c := nextInt()
			adj[u][v] = c
		}
	}

	// for i := range adj {
	// 	fmt.Println(adj[i])
	// }

	dist := make([]int, n)
	prev := make([]int, n)
	visited := make([]bool, n)
	dijkstra := func(start int, size int) {
		for i := 0; i < size; i++ {
			dist[i] = INF
			prev[i] = -1
			visited[i] = false
		}
		dist[start] = 0
		for {
			u := -1
			tmp_min := INF
			for i := 0; i < size; i++ {
				if visited[i] == false && dist[i] < tmp_min {
					tmp_min = dist[i]
					u = i
				}
			}
			if u == -1 {
				break
			}
			visited[u] = true
			for i := 0; i < size; i++ {
				if adj[u][i] > 0 {
					w := adj[u][i]
					newlen := dist[u] + w
					if newlen < dist[i] {
						dist[i] = newlen
						prev[i] = u
					}
				}
			}
		}
	}
	dijkstra(0, n)
	for i, cost := range dist {
		fmt.Printf("%d %d\n", i, cost)
	}
}

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;
    }
}