Go: package main

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

const NIL = -1

type Node struct {
	id     int
	weight int
}

func init() {
	sc.Split(bufio.ScanWords)
}

type NodeHeap []Node

func (h NodeHeap) Len() int           { return len(h) }
func (h NodeHeap) Less(i, j int) bool { return h[i].weight < h[j].weight }
func (h NodeHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *NodeHeap) Push(x interface{}) {
	*h = append(*h, x.(Node))
}

func (h *NodeHeap) Pop() interface{} {
	old := *h
	n := len(old)
	x := old[n-1]
	*h = old[0 : n-1]
	return x
}

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func main() {
	n := scanInt()

	list := make([][]int, n)
	weight := make([]int, n)
	for i := range list {
		list[i] = make([]int, n)
		weight[i] = NIL
		for j := range list[i] {
			list[i][j] = NIL
		}
	}

	for i := 0; i < n; i++ {
		u := scanInt()
		k := scanInt()
		for j := 0; j < k; j++ {
			v := scanInt()
			w := scanInt()
			list[u][v] = w
		}
	}

	start := Node{id: 0, weight: 0}
	h := &NodeHeap{start}
	heap.Init(h)

	for h.Len() > 0 {
		node := heap.Pop(h).(Node)
		if weight[node.id] != NIL {
			continue
		}
		weight[node.id] = node.weight

		for i, w := range list[node.id] {
			if w == NIL {
				continue
			}
			heap.Push(h, Node{id: i, weight: w + node.weight})
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		fmt.Fprint(w, i)
		fmt.Fprint(w, " ")
		fmt.Fprint(w, weight[i])
		fmt.Fprintln(w)
	}
	w.Flush()
}

C++: #include <iostream>
#include <vector>
#define INF 1e9
using namespace std;

int main(){
    //declaration and input
    int n;
    cin >> n;
    int u, k;
    vector<vector<int>> graph(n, vector<int>(n, INF));
    for (int i = 0; i < n; i++){
        cin >> u >> k;
        int v, c;
        for (int j = 0; j < k; j++){
            cin >> v >> c;
            graph[u][v] = c;
        }
    }
    vector<int> cost(n, INF);
    vector<int> parent_of(n, -1);
    vector<bool> is_visit(n, false);

    //Dijkstra
    //init
    cost[0] = 0;
    
    //loop
    while(true){
        int mincost = INF;
        int next = -1;
        for (int i = 0; i < n; i++){
            if (!is_visit[i] && cost[i] < mincost){
                mincost = cost[i];
                next = i;
            }
        }
        if (next == -1)
            break;
        is_visit[next] = true;
        for (int i = 0; i < n; i++){
            if (!is_visit[i] && graph[next][i] < INF){
                if (cost[next] + graph[next][i] < cost[i]){
                    cost[i] = cost[next] + graph[next][i];
                    parent_of[i] = next;
                }
            }
        }
    }

    //output
    for (int i = 0; i < n; i++)
        cout << i << ' ' << cost[i] << endl;
    return 0;
}

C++: #include <iostream>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>	// require sort next_permutation count __gcd reverse etc.
#include <cstdlib>	// require abs exit atof atoi 
#include <cstdio>		// require scanf printf
#include <functional>
#include <numeric>	// require accumulate
#include <cmath>		// require fabs
#include <climits>
#include <limits>
#include <cfloat>
#include <iomanip>	// require setw
#include <sstream>	// require stringstream 
#include <cstring>	// require memset
#include <cctype>		// require tolower, toupper
#include <fstream>	// require freopen
#include <ctime>		// require srand
#define rep(i,n) for(int i=0;i<(n);i++)
#define ALL(A) A.begin(), A.end()
#define INF 1<<20

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

int cost[105][105];
int d[105];
bool used[105];

int dijkstra (int n )
{
	memset (used, false, sizeof (used ) );
	fill (d, d+n, INF );
	d[0] = 0;

	while (true ){
		int v = -1;
		// まだ使われていない頂点のうち距離が最小のものを探す
		rep (u, n )
			if (!used[u] && (v == -1 || d[u] < d[v] ) ) v = u;
		
		if (v == -1 ) break;
		
		used[v] = true;
		rep (u, n )
			d[u] = min (d[u], d[v] + cost[v][u] );
	} // end whle
}

int main()
{
	ios_base::sync_with_stdio(0);
	int n; cin >> n;
	rep (i, n ) rep (j, n ) cost[i][j] = INF;

	rep (i, n ){
		int u; cin >> u;
		int k; cin >> k;
		while (k-- ){
			int v, c; cin >> v >> c;
			cost[u][v] = c;
		} // end while
	} // end loop

	dijkstra (n );
	rep (i, n ) cout << i << ' ' << d[i] << endl;
		
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <map>
#include <queue>


void update(int node, std::vector<int>& weight, const std::vector<std::map<int, int>> link_list) {
    for (auto && l : link_list[node]) {
        if (weight[l.first] == -1 || weight[node] + l.second < weight[l.first]) {
            weight[l.first] = weight[node] + l.second;
            update(l.first, weight, link_list);
        }
    }
}


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

    std::vector<std::map<int, int>> link_list;
    for (int i = 0; i < n; i++) {
        int u, k;
        std::cin >> u >> k;
        std::map<int, int> map;
        for (int j = 0; j < k; j++) {
            int c, v;
            std::cin >> c >> v;
            map[c] = v;
        }
        link_list.emplace_back(map);
    }

    std::vector<int> weight(n, -1);
    weight[0] = 0;

    auto comp = [] (std::tuple<int, int, int> &lfs, std::tuple<int, int, int> &rhs) {
        return std::get<2>(lfs) > std::get<2>(rhs);
    };
    
    std::priority_queue<std::tuple<int, int, int>, std::vector<std::tuple<int, int, int>>, decltype(comp)> que(comp);
    for (auto && m : link_list[0]) {
        que.push(std::make_tuple(0, m.first, m.second));
    }

    while (!que.empty()) {
        auto val = que.top();
        que.pop();
        auto w = weight[std::get<0>(val)] + std::get<2>(val);
        if (weight[std::get<1>(val)] == -1 || w < weight[std::get<1>(val)]) {
            weight[std::get<1>(val)] = w;
            for (auto && m : link_list[std::get<1>(val)]) {
                que.push(std::make_tuple(std::get<1>(val), m.first, m.second));
            }
        }
    }

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