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 <algorithm>
using namespace std;

#define MAX_VERTEX 100
#define INF 1000000

int vertex_num;   // ???????????°

int cost[MAX_VERTEX][MAX_VERTEX]; // ????????????cost[?§????][??????]??§?§?????????????????????????????????¨???
int d[MAX_VERTEX];                // ????????????d[u]??§?§??????¨u??????????????¢?????¨??????
bool used[MAX_VERTEX];            // ????????????????????£????????¢????±???????????????????

void Input() {
	cin >> vertex_num;

	// (a1) ??\???????????¶??§?????????
	// d??¨cost?????¨???INF
	// used????????????false
	for (int i = 0; i < vertex_num;i++){
		d[i] = INF;
		used[i] = false;
		for (int j = 0; j < vertex_num;j++){
			cost[i][j] = INF;
		}
	}

	for (int i = 0; i < vertex_num; i++) {
		int from, out_num;
		cin >> from >> out_num;
		for (int j = 0; j < out_num; j++) {
			int to, c;
			cin >> to >> c;
			cost[from][to] = c;
		}
	}
}

void Dijkstra() {
	// (b1) ?§????????????????
	d[0] = 0;
	while (true) {
		// ????????????????????¨???
		int vertex = -1;

		// (b2) ????????????????????£????????¢????±??????????????????????
		// ?????????????????????????????????????????§????????¢???????°???????????????¢???
		for (int i = 0; i < vertex_num; i++){
			if (!used[i] && (vertex == -1 || d[i] < d[vertex])){
				vertex = i;
			}
		}

		// ??¨????????????????????????????¨?????????????????????´????????????????????????
		if (vertex == -1) break;

		used[vertex] = true;

		// ???????????¢????¨????????????????
		for (int u = 0; u < vertex_num; u++) {
			d[u] = min(d[u], d[vertex] + cost[vertex][u]);
		}

	}

}

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

int main() {

	Input();
	Dijkstra();
	Output();

	return 0;
}