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>
using namespace std;
#include<stdio.h>

int main()
{
    int n, m, i, j, a, w;
    int* adj[100];
    int* dist[100];
    scanf("%d", &n);
    for(i = 0; i < n; i++){
        scanf("%d %d", &i, &m);
        adj[i] = new int [m + 1];
        dist[i] = new int [m + 1];
        for(j = 0; j < m; j++){
            scanf("%d %d", &a, &w);
            adj[i][j] = a;
            dist[i][j] = w;
        }
        adj[i][m] = -1;
        dist[i][m] = -1;
    }
    int *d, *prev, *Q;
    d = new int [n];
    prev = new int [n];
    Q = new int [n];
    for(i = 0; i < n; i++){ d[i] = 200000; prev[i] = -1; Q[i] = i; }
    int rest = n;

    int u, v, min;
    d[0] = 0;
    while(rest > 0){
        min = 200000;
        for(i = 0; i < n; i++){
            if(min > d[i] && Q[i] >= 0){ min = d[i]; u = i; }
        }
        Q[u] = -1;
        rest--;

        for(j = 0; adj[u][j] >= 0; j++){
            v = adj[u][j];
            if(d[v] > d[u] + dist[u][j]){
                d[v] = d[u] + dist[u][j];
                prev[v] = u;
            }
        }
    };
    for(i = 0; i < n; i++){ printf("%d %d\n", i, d[i]); }
    for(i = 0; i < n; i++){
        delete adj[i]; delete dist[i]; }
    delete d;
    delete prev;
    delete Q;
 
    return 0;
}