我正在尝试计算删除族树中节点的最佳方法。首先，对应用程序的工作方式进行一些描述。
我的应用程序做出以下假设：
任何节点只能有一个合作伙伴。这意味着单个节点拥有的任何子节点，它也将是伙伴节点子节点。因此，阶梯关系，离婚等不予补偿。节点总是有两个父母 - 母亲和父亲不能单独添加。如果用户不知道详细信息 - 节点属性设置为默认值。
此外，任何节点都可以将父母，兄弟姐妹和孩子添加到自身。因此，在法律上可以增加关系。
编辑：在研究了Andreas的回答之后，我逐渐意识到我的代码可能需要一些重新工作。我正在尝试添加我的源代码，但它超出了charracters的限制......有什么建议吗？以下是FamilyTree类：
package familytree;
import java.io.PrintStream;
public class FamilyTree {
private static final int DISPLAY_FAMILY_MEMBERS = 1;
private static final int ADD_FAMILY_MEMBER = 2;
private static final int REMOVE_FAMILY_MEMBER = 3;
private static final int EDIT_FAMILY_MEMBER = 4;
private static final int SAVE_FAMILY_TREE = 5;
private static final int LOAD_FAMILY_TREE = 6;
private static final int DISPLAY_ANCESTORS = 7;
private static final int DISPLAY_DESCENDANTS = 8;
private static final int QUIT = 9;
private Input in;
private Family family;
private PrintStream out;
public FamilyTree(Input in, PrintStream out) {
this.in = in;
this.out = out;
family = new Family();
}
public void start() {
out.println("\nWelcome to the Family Tree Builder");
initialise();
while (true) {
displayFamilyTreeMenu();
int command = getCommand();
if (quit(command)) {
break;
}
executeOption(command);
}
}
private int getCommand() {
return getInteger("\nEnter command: ");
}
private int getInteger(String message) {
while (true) {
out.print(message);
if (in.hasNextInt()) {
int n = in.nextInt();
in.nextLine();
return n;
} else {
in.nextLine();
out.println("Your input was not understood. Please try again.");
}
}
}
//good
private void displayFamilyTreeMenu() {
out.println("\nFamily Tree Menu");
out.println(DISPLAY_FAMILY_MEMBERS + ". Display Family Members");
out.println(ADD_FAMILY_MEMBER + ". Add Family Member");
out.println(REMOVE_FAMILY_MEMBER + ". Remove Family Member");
out.println(EDIT_FAMILY_MEMBER + ". Edit Family Member");
out.println(SAVE_FAMILY_TREE + ". Save Family Tree");
out.println(LOAD_FAMILY_TREE + ". Load Family Tree");
out.println(DISPLAY_ANCESTORS + ". Display Ancestors");
out.println(DISPLAY_DESCENDANTS + ". Display Descendants");
out.println(QUIT + ". Quit");
}
//good
private boolean quit(int opt) {
return (opt == QUIT) ? true : false;
}
//good
private void executeOption(int choice) {
switch (choice) {
case DISPLAY_FAMILY_MEMBERS:
displayFamilyMembers();
break;
case ADD_FAMILY_MEMBER:
addFamilyMember();
break;
case REMOVE_FAMILY_MEMBER:
removeMember();
break;
case EDIT_FAMILY_MEMBER:
editMember();
break;
case SAVE_FAMILY_TREE:
saveFamilyTree();
break;
case LOAD_FAMILY_TREE:
loadFamilyTree();
break;
case DISPLAY_ANCESTORS:
displayAncestors();
break;
case DISPLAY_DESCENDANTS:
displayDescendants();
break;
default:
out.println("Not a valid option! Try again.");
break;
}
}
private void removeMember() {
displayFamilyMembers();
int choice = selectMember();
if (choice >= 0) {
FamilyMember f = family.getFamilyMember(choice);
if (f.getIndex() == 0) {
out.println("Cannot delete yourself!");
return;
}
deleteMember(f);
}
}
private void deleteMember(FamilyMember f) {
//remove from tree
family.removeMember(f);
//remove all links to this person
if (f.hasParents()) {
f.getMother().removeChild(f);
f.getFather().removeChild(f);
}
if(f.getPartner()!=null){
f.getPartner().setPartner(null);
f.setPartner(null);
}
if (f.hasChildren()) {
for (FamilyMember member : f.getChildren()) {
if (f == member.getMother()) {
member.setMother(null);
}
if (f == member.getFather()) {
member.setFather(null);
}
if (f == member.getPartner()) {
member.setPartner(null);
}
}
}
}
private void saveFamilyTree() {
out.print("Enter file name: ");
String fileName = in.nextLine();
FileOutput output = new FileOutput(fileName);
family.save(output);
output.close();
saveRelationships();
}
private void saveRelationships() {
FileOutput output = new FileOutput("Relationships.txt");
family.saveRelationships(output);
output.close();
}
private void loadFamilyTree() {
out.print("Enter file name: ");
String fileName = in.nextLine();
FileInput input = new FileInput(fileName);
family.load(input);
input.close();
loadRelationships();
}
private void loadRelationships() {
FileInput input = new FileInput("Relationships.txt");
family.loadRelationships(input);
input.close();
}
//for selecting family member for editing adding nodes etc
private void displayFamilyMembers() {
out.println("\nDisplay Family Members");
int count = 0;
for (FamilyMember member : family.getFamilyMembers()) {
out.println();
if (count + 1 < 10) {
out.println((count + 1) + ". " + member.getFirstName() + " " + member.getLastName());
out.println(" " + member.getGender());
out.println(" " + member.getDob());
out.println(" Generation: " + (member.getGeneration() + 1));
} else {
out.println((count + 1) + ". " + member.getFirstName() + " " + member.getLastName());
out.println(" " + member.getGender());
out.println(" " + member.getDob());
out.println(" Generation: " + (member.getGeneration() + 1));
}
count++;
}
}
private int selectRelative() {
out.println("\nSelect Relative");
out.println("1. Add Parents");
out.println("2. Add Child");
out.println("3. Add Partner");
out.println("4. Add Sibling");
//out.print("\nEnter Choice: ");
//int choice = in.nextInt();
int choice = getInteger("\nEnter Choice: ");
if (choice > 0 && choice < 5) {
return choice;
}
return (-1);
}
private void addFamilyMember() {
if (family.getFamilyMembers().isEmpty()) {
out.println("No Members To Add To");
return;
}
int memberIndex = selectMember();
if (memberIndex >= 0) {
FamilyMember member = family.getFamilyMember(memberIndex);
int relative = selectRelative();
if (relative > 0) {
out.println("\nAdd Member");
//if choice is valid
switch (relative) {
case 1:
//adding parents
FamilyMember mum, dad;
if (!member.hasParents()) {
out.println("Enter Mothers Details");
mum = addMember(relative, "Female");
out.println("\nEnter Fathers Details");
dad = addMember(relative, "Male");
member.linkParent(mum);
member.linkParent(dad);
mum.linkPartner(dad);
mum.setGeneration(member.getGeneration() - 1);
dad.setGeneration(member.getGeneration() - 1);
sortGenerations();
} else {
out.println(member.getFirstName() + " " + member.getLastName() + " already has parents.");
}
break;
case 2:
//adding child
if (member.getPartner() == null) {
FamilyMember partner;
if (member.getGender().equals("Male")) {
out.println("Enter Mothers Details");
partner = addMember(1, "Female");
} else {
out.println("Enter Fathers Details");
partner = addMember(1, "Male");
}
//create partner
member.linkPartner(partner);
partner.setGeneration(member.getGeneration());
out.println();
}
out.println("Enter Childs Details");
FamilyMember child = addMember(relative, "");
child.linkParent(member);
child.linkParent(member.getPartner());
child.setGeneration(member.getGeneration() + 1);
sortGenerations();
break;
case 3:
//adding partner
if (member.getPartner() == null) {
out.println("Enter Partners Details");
FamilyMember partner = addMember(relative, "");
member.linkPartner(partner);
partner.setGeneration(member.getGeneration());
} else {
out.println(member.getFirstName() + " " + member.getLastName() + " already has a partner.");
}
break;
case 4:
//adding sibling
if (member.getFather() == null) {
out.println("Enter Mothers Details");
mum = addMember(1, "Female");
out.println("\nEnter Fathers Details");
dad = addMember(1, "Male");
member.linkParent(mum);
member.linkParent(dad);
mum.linkPartner(dad);
mum.setGeneration(member.getGeneration() - 1);
dad.setGeneration(member.getGeneration() - 1);
sortGenerations();
out.println("\nEnter Siblings Details");
} else {
out.println("Enter Siblings Details");
}
FamilyMember sibling = addMember(relative, "");
//create mum and dad
mum = member.getMother();
dad = member.getFather();
sibling.linkParent(mum);
sibling.linkParent(dad);
sibling.setGeneration(member.getGeneration());
break;
}
} else {
out.println("Invalid Option!");
}
} else {
out.println("Invalid Option!");
}
}
private int selectMember() {
displayFamilyMembers();
//out.print("\nSelect Member: ");
//int choice = in.nextInt();
int choice = getInteger("\nSelect Member: ");
if (choice > 0 && choice <= family.getFamilyMembers().size()) {
return (choice - 1);
}
return -1;
}
private void editMember() {
int choice = selectMember();
if (choice >= 0) {
out.println("Select Detail To Edit: ");
out.println("1. Name");
out.println("2. Gender");
out.println("3. Date of Birth");
//out.print("\nEnter Choice: ");
//int opt = in.nextInt();
int opt = getInteger("\nEnter Choice: ");
if (opt > 0 && opt < 4) {
switch (opt) {
case 1: //name
out.print("Enter New First Name: ");
String fName = in.nextLine();
out.print("Enter New Last Name: ");
String lName = in.nextLine();
family.changeName(fName, lName, choice);
break;
case 2: //Gender
FamilyMember f = family.getFamilyMember(choice);
String gender = f.getGender();
if (f.getChildren().isEmpty()) {
gender = selectGender();
family.changeGender(gender, choice);
} else {
//swap genders
//swap mother father relationships for kids
swapGenders(f, choice);
}
break;
case 3:
String dob = enterDateOfBirth();
family.changeDOB(dob, choice);
}
} else {
out.println("Invalid Choice!");
}
}
}
private FamilyMember addMember(int option, String gender) {
out.print("Enter First Name: ");
String fName = formatString(in.nextLine().trim());
out.print("Enter Last Name: ");
String lName = formatString(in.nextLine().trim());
//String gender;
if (option != 1) { //if not adding parents
gender = selectGender();
}
String dob = enterDateOfBirth();
FamilyMember f = family.getFamilyMember(family.addMember(fName, lName, gender, dob));
f.setIndex(family.getFamilyMembers().size() - 1);
return (f);
}
private String selectGender() {
String gender = null;
out.println("Select Gender");
out.println("1. Male");
out.println("2. Female");
//out.print("Enter Choice: ");
//int gOpt = in.nextInt();
int gOpt = getInteger("Enter Choice: ");
if (gOpt == 1) {
gender = "Male";
} else if (gOpt == 2) {
gender = "Female";
} else {
out.println("Invalid Choice");
}
return gender;
}
private void swapGenders(FamilyMember f, int choice) {
String gender;
out.println("\nNOTE: Editing A Parent Nodes Gender Will Swap Parents Genders\n"
+ "And Swap Mother/Father Relationships For All Children.");
out.println("\nContinue:");
out.println("1. Yes");
out.println("2. No");
//out.print("\nEnter Choice: ");
//int select = in.nextInt();
int select = getInteger("\nEnter Choice: ");
if (select > 0 && select < 3) {
switch (select) {
case 1:
//swap relationships
gender = selectGender();
//if selected gender is different
if (!gender.equals(f.getGender())) {
//swap
String g = f.getGender();
family.changeGender(gender, choice);
family.changeGender(g, f.getPartner().getIndex());
if (g.equals("Male")) {
for (FamilyMember m : f.getChildren()) {
m.setMother(f);
m.setFather(f.getPartner());
}
} else {
for (FamilyMember m : f.getChildren()) {
m.setFather(f);
m.setMother(f.getPartner());
}
}
}
break;
case 2:
break;
}
} else {
out.println("Invalid Choice");
}
}
private String formatString(String s) {
String firstLetter = s.substring(0, 1);
String remainingLetters = s.substring(1, s.length());
s = firstLetter.toUpperCase() + remainingLetters.toLowerCase();
return s;
}
private String enterDateOfBirth() {
out.print("Enter Year Of Birth (0 - 2011): ");
String y = in.nextLine();
out.print("Enter Month Of Birth (1-12): ");
String m = in.nextLine();
if (m.trim().equals("")) {
m = "0";
}
if (Integer.parseInt(m) < 10) {
m = "0" + m;
}
m += "-";
out.print("Enter Date of Birth (1-31): ");
String d = in.nextLine();
if (d.trim().equals("")) {
d = "0";
}
if (Integer.parseInt(d) < 10) {
d = "0" + d;
}
d += "-";
String dob = d + m + y;
while (!DateValidator.isValid(dob)) {
out.println("Invalid Date. Try Again:");
dob = enterDateOfBirth();
}
return (dob);
}
private void displayAncestors() {
out.print("\nDisplay Ancestors For Which Member: ");
int choice = selectMember();
if (choice >= 0) {
FamilyMember node = family.getFamilyMember(choice);
FamilyMember ms = findRootNode(node, 0, 2, -1);
FamilyMember fs = findRootNode(node, 1, 2, -1);
out.println("\nPrint Ancestors");
out.println("\nMothers Side");
if(ms==null){
out.println("Member has no mother");
}else{
printDescendants(ms, node, ms.getGeneration());
}
out.println("\nFathers Side");
if(fs==null){
out.println("Member has no father");
}else{
printDescendants(fs, node, fs.getGeneration());
}
} else {
out.println("Invalid Option!");
}
}
private void displayDescendants() {
out.print("\nDisplay Descendants For Which Member: ");
int choice = selectMember();
if (choice >= 0) {
FamilyMember node = family.getFamilyMember(choice);
out.println("\nPrint Descendants");
printDescendants(node, null, 0);
} else {
out.println("Invalid Option!");
}
}
private FamilyMember findRootNode(FamilyMember node, int parent, int numGenerations, int count) {
FamilyMember root;
count++;
if (count < numGenerations) {
if (parent == 0) {
if(node.hasMother()){
node = node.getMother();
}else{
return node;
}
} else {
if(node.hasFather()){
node = node.getFather();
}else{
return node;
}
}
root = findRootNode(node, 1, numGenerations, count);
return root;
}
return node;
}
private int findHighestLeafGeneration(FamilyMember node) {
int gen = node.getGeneration();
for (int i = 0; i < node.getChildren().size(); i++) {
int highestChild = findHighestLeafGeneration(node.getChild(i));
if (highestChild > gen) {
gen = highestChild;
}
}
return gen;
}
private void printDescendants(FamilyMember root, FamilyMember node, int gen) {
out.print((root.getGeneration() + 1) + " " + root.getFullName());
out.print(" [" + root.getDob() + "] ");
if (root.getPartner() != null) {
out.print("+Partner: " + root.getPartner().getFullName() + " [" + root.getPartner().getDob() + "] ");
}
if (root == node) {
out.print("*");
}
out.println();
if (!root.getChildren().isEmpty() && root != node) {
for (int i = 0; i < root.getChildren().size(); i++) {
for (int j = 0; j < root.getChild(i).getGeneration() - gen; j++) {
out.print(" ");
}
printDescendants(root.getChild(i), node, gen);
}
} else {
return;
}
}
//retrieve highest generation
public int getRootGeneration() {
int min = family.getFamilyMember(0).getGeneration();
for (int i = 0; i < family.getFamilyMembers().size(); i++) {
min = Math.min(min, family.getFamilyMember(i).getGeneration());
}
return Math.abs(min);
}
public void sortGenerations() {
int amount = getRootGeneration();
for (FamilyMember member : family.getFamilyMembers()) {
member.setGeneration(member.getGeneration() + amount);
}
}
//test method - temporary
private void initialise() {
family.addMember("Bart", "Simpson", "Male", "18-03-1985");
family.getFamilyMember(0).setIndex(0);
family.addMember("Homer", "Simpson", "Male", "24-09-1957");
family.getFamilyMember(1).setIndex(1);
family.addMember("Marge", "Simpson", "Female", "20-07-1960");
family.getFamilyMember(2).setIndex(2);
family.addMember("Lisa", "Simpson", "Female", "28-01-1991");
family.getFamilyMember(3).setIndex(3);
family.addMember("Abe", "Simpson", "Male", "10-03-1920");
family.getFamilyMember(4).setIndex(4);
family.addMember("Mona", "Simpson", "Female", "18-09-1921");
family.getFamilyMember(5).setIndex(5);
//set relationships
family.getFamilyMember(0).setMother(family.getFamilyMember(2));
family.getFamilyMember(0).setFather(family.getFamilyMember(1));
family.getFamilyMember(3).setMother(family.getFamilyMember(2));
family.getFamilyMember(3).setFather(family.getFamilyMember(1));
family.getFamilyMember(1).addChild(family.getFamilyMember(3));
family.getFamilyMember(1).addChild(family.getFamilyMember(0));
family.getFamilyMember(2).addChild(family.getFamilyMember(3));
family.getFamilyMember(2).addChild(family.getFamilyMember(0));
family.getFamilyMember(1).setPartner(family.getFamilyMember(2));
family.getFamilyMember(2).setPartner(family.getFamilyMember(1));
family.getFamilyMember(4).setPartner(family.getFamilyMember(5));
family.getFamilyMember(5).setPartner(family.getFamilyMember(4));
family.getFamilyMember(1).setMother(family.getFamilyMember(5));
family.getFamilyMember(1).setFather(family.getFamilyMember(4));
family.getFamilyMember(4).addChild(family.getFamilyMember(1));
family.getFamilyMember(5).addChild(family.getFamilyMember(1));
family.getFamilyMember(0).setGeneration(2);
family.getFamilyMember(1).setGeneration(1);
family.getFamilyMember(2).setGeneration(1);
family.getFamilyMember(3).setGeneration(2);
family.getFamilyMember(4).setGeneration(0);
family.getFamilyMember(5).setGeneration(0);
}
}
答案 0 :(得分：3)
所有任务都需要同样的努力。总会这样：
public void deleteFamilyMember(FamilyMember member) {
member.mother.children.remove(member);
member.father.children.remove(member);
member.partner.children.remove(member);
for (FamilyMember child:children) {
if (child.father == member) child.father = null;
if (child.mother == member) child.mother = null;
if (child.partner == member) child.partner = null;
}
// now all references to this member are eliminated, gc will do the rest.
}
示例：
Homer.mother = ??
Homer.father = ??
Homer.partner = Marge
Homer.children = {Bart, Lisa, Maggie}
Marge.mother = ??
Marge.father = ??
Marge.partner = Homer
Marge.children = {Bart, Lisa, Maggie}
Bart.mother = Marge
Bart.father = Homer
Bart.partner = null
Bart.children = {}
Lisa.mother = Marge
Lisa.father = Homer
Lisa.partner = null
Lisa.children = {}
Maggie.mother = Marge
Maggie.father = Homer
Maggie.partner = null
Maggie.children = {}
要从家族树中删除Bart，我们应该将Bart的母亲和父亲属性设置为null并且需要将Bart从Homer和Marge的列表中移除孩子。
要移除Marge，我们必须将其合作伙伴的合作伙伴设为null（Homer.partner）并访问所有子项以清除其mother属性（这是上面代码的child.mother部分）
答案 1 :(得分：1)
我会以不同的方式对事物进行建模，并在FamilyMember类中完成工作。这是一个示例实现：
public class FamilyMember{
public enum Gender{
MALE, FEMALE
}
private final Set<FamilyMember> exPartners =
new LinkedHashSet<FamilyMember>();
public Set<FamilyMember> getExPartners(){
return new LinkedHashSet<FamilyMember>(exPartners);
}
public FamilyMember getFather(){
return father;
}
public FamilyMember getMother(){
return mother;
}
public Set<FamilyMember> getSiblings(){
final Set<FamilyMember> set =
father == null && mother == null ? Collections
.<FamilyMember> emptySet() : new HashSet<FamilyMember>();
if(father != null){
set.addAll(father.children);
}
if(mother != null){
set.addAll(mother.children);
}
set.remove(this);
return set;
}
public String getName(){
return name;
}
private final Gender gender;
private FamilyMember partner;
private final FamilyMember father;
private final FamilyMember mother;
private final Set<FamilyMember> children =
new LinkedHashSet<FamilyMember>();
private final String name;
public FamilyMember haveChild(final String name, final Gender gender){
if(partner == null){
throw new IllegalStateException("Partner needed");
}
final FamilyMember father = gender == Gender.MALE ? this : partner;
final FamilyMember mother = father == this ? partner : this;
return new FamilyMember(father, mother, name, gender);
}
public Set<FamilyMember> getChildren(){
return new LinkedHashSet<FamilyMember>(children);
}
@Override
public String toString(){
return "[" + name + ", " + gender + "]";
}
public FamilyMember(final String name, final Gender gender){
this(null, null, name, gender);
}
public FamilyMember(final FamilyMember father,
final FamilyMember mother,
final String name,
final Gender gender){
if(name == null){
throw new IllegalArgumentException("A kid needs a name!");
}
if(gender == null){
throw new IllegalArgumentException("Which is it going to be?");
}
this.father = father;
this.name = name;
this.gender = gender;
if(father != null){
father.children.add(this);
}
this.mother = mother;
if(mother != null){
mother.children.add(this);
}
}
public FamilyMember hookUpWith(final FamilyMember partner){
if(partner.gender == gender){
throw new IllegalArgumentException(
"Sorry, same-sex-marriage would make things too complicated");
}
this.partner = partner;
partner.partner = this;
return this;
}
public FamilyMember splitUp(){
if(partner == null){
throw new IllegalArgumentException("Hey, I don't have a partner");
} else{
partner.partner = null;
exPartners.add(partner);
partner.exPartners.add(this);
partner = null;
}
return this;
}
public FamilyMember getPartner(){
return partner;
}
}
这是你可以用这种方式编写的更具表现力的代码：
FamilyMember marge = new FamilyMember("Marge", Gender.FEMALE);
FamilyMember homer = new FamilyMember("Homer", Gender.MALE);
homer.hookUpWith(marge);
FamilyMember bart = homer.haveChild("Bart", Gender.MALE);
FamilyMember lisa = marge.haveChild("Lisa", Gender.FEMALE);
System.out.println("Homer & Marge: " + marge + ", "
+ marge.getPartner());
homer.splitUp();
FamilyMember dolores =
marge
.hookUpWith(new FamilyMember("New Guy", Gender.MALE))
.haveChild("Dolores", Gender.FEMALE);
FamilyMember bruno =
homer
.hookUpWith(new FamilyMember("New Girl", Gender.FEMALE))
.haveChild("Bruno", Gender.MALE);
System.out.println(
"Marge & Partner: " + marge + ", " + marge.getPartner());
System.out.println("Marge's Ex-Partners: " + marge.getExPartners());
System.out.println(
"Homer & Partner: " + homer + ", " + homer.getPartner());
System.out.println("Homer's Ex-Partners: " + homer.getExPartners());
System.out.println("Marge's kids: " + marge.getChildren());
System.out.println("Homer's kids: " + homer.getChildren());
System.out.println("Dolores's siblings: " + dolores.getSiblings());
System.out.println("Brunos's siblings: " + bruno.getSiblings());
输出：
荷马＆amp; Marge：[Marge，FEMALE]，[Homer，MALE]
Marge＆amp;合伙人：[Marge，FEMALE]，[New Guy，MALE]
Marge的前合伙人：[[Homer，MALE]]
荷马＆amp;合伙人：[荷马，男性]，[新女孩，女性]
荷马的前合伙人：[[Marge，FEMALE]]
Marge的孩子：[[Bart，MALE]，[Lisa，FEMALE]，[Dolores，FEMALE]]
荷马的孩子：[[巴特，男士]，[丽莎，女]，[布鲁诺，男]] 多洛雷斯的兄弟姐妹：[[Bart，MALE]，[Lisa，FEMALE]]
Brunos的兄弟姐妹：[[Bart，MALE]，[Lisa，FEMALE]]