#include <iostream>
#include <string>
using namespace std;
class Person{
public:
string name;
int age, height, weight;
Person(string name = "empty", int age = 0, int height = 0, int weight = 0) {
this->name = name;
this->age = age;
this->height = height;
this->weight = weight;
}
Person operator = (const Person &P) {
name = P.name;
age = P.age;
height = P.height;
weight = P.weight;
return *this;
}
void setAge(int a){
age = a;
}
int getAge(){
return age;
}
friend ostream& operator<<(ostream& os, const Person& p);
};
ostream& operator<<(ostream& os, Person& p) {
os << "Name: " << p.name << " " << "Age: " << p.age << " " << "Height: " << p.height << " " << "Weight: " << p.weight << "\n";
return os;
};
class Node {
public:
Person* data;
Node* next;
Node(Person*A) {
data = A;
next = nullptr;
}
};
class LinkedList {
public:
Node * head;
LinkedList() {
head = nullptr;
}
void InsertAtHead(Person*A) {
Node* node = new Node(A);
node->next = head;
head = node;
}
void InsertAtEnd(Person*A) {
if (head == nullptr) {
InsertAtHead(A);
}
else {
Node* node = new Node(A);
Node* temp = head;
while (temp->next != nullptr) {
temp = temp->next;
}
temp->next = node;
}
}
void InsertAtPosition(Person*A, int pos) {
if (head == nullptr) {
InsertAtHead(A);
}
else {
Node* node = new Node(A);
Node* temp = head;
for (int i = 1; i < pos - 1; i++) { temp = temp->next; }
node->next = temp->next;
temp->next = node;
}
}
void DeleteByValue(string search_name) {
Node* temp = head;
Node* prev = nullptr;
while (temp != nullptr) {
if (temp->data->name == search_name) {
if (prev != nullptr) {
prev->next = temp->next;
}
else {
head = temp->next;
}
delete temp;
temp = nullptr;
}
else {
prev = temp;
temp = temp->next;
}
}
}
void DeleteFromHead() {
if (head != nullptr) {
Node* temp = head;
head = head->next;
delete temp;
}
}
void DeleteFromEnd() {
Node* prev = nullptr;
Node* temp = head;
if (head == nullptr) { cout << "Nothing to delete" << endl; }
else if (head->next == nullptr) { DeleteFromHead(); }
else {
while (temp->next != nullptr) {
prev = temp;
temp = temp->next;
}
prev->next = nullptr;
delete temp;
}
}
void DeleteAtPosition(int pos) {
Node* prev = nullptr;
Node* temp = head;
if (head == nullptr) { cout << "Nothing to delete" << endl; }
else if (pos == 1) { DeleteFromHead(); }
else {
for (int i = 1; i < pos; i++) {
prev = temp;
temp = temp->next;
}
prev->next = temp->next;
delete temp;
}
}
void UpdateAtPosition(Person*A, int pos) {
if (head == nullptr) { cout << "No element in the list"; return; }
if (pos == 1) { head->data = A; }
else {
Node* temp = head;
for (int i = 1; i < pos; i++) {
temp = temp->next;
}
temp->data = A;
}
}
void UpdateByValue(string name, int newAge) {
Node* temp = head;
Person* p = new Person();
while(temp != nullptr){
if(temp->data->name == name){
p->setAge(newAge);
}else{
temp = temp->next;
}
}
}
void Print() {
Node* temp = head;
while (temp != nullptr) {
cout << *(temp->data);
temp = temp->next;
}
cout << endl;
}
};
int main() {
LinkedList* list = new LinkedList();
list->InsertAtHead(new Person("Samantha", 20, 63, 115)); list->Print();
list->InsertAtEnd(new Person("Chris", 19, 70, 200)); list->Print();
list->DeleteByValue("Chris"); list->Print();
list->UpdateByValue("Samantha", 21); list->Print();
return 0;
}
我是C ++的新手,所以请原谅任何写得不好的代码,但是我想使用UpdateByValue函数来更新Samantha的年龄。现在可能看起来很不对劲,但是我尝试了20种不同的方法,无法弄清楚我在做什么错。我曾经在社区学院上过学,在那里我学习了Java,因此Im赶上了所有使用C ++的人。很多地方都是相似的,但我却为这样的小事情而苦恼。谁能向我解释如何修复UpdateByValue函数,以使其更改我选择的Person对象的年龄?我希望能够将名称输入为第一个参数,并使用第二个参数更改该人的年龄。如果不清楚并需要更多说明,请告诉我,我只需要帮助。在此先感谢您,并随时提出其他任何建设性的批评。我正在努力使自己变得更好。
最佳答案
让我们来看一下UpdateByValue
。我会评论。
void UpdateByValue(string name, int newAge) {
Node* temp = head;
Person* p = new Person();
while(temp != nullptr){ // keep looking until end of list
if(temp->data->name == name){ // found node with name
p->setAge(newAge); // update a different node
// never advance node so we can't exit function
}else{
temp = temp->next;
}
}
}
试试吧
void UpdateByValue(string name, int newAge) {
Node* temp = head;
// Person * p is not needed
while(temp != nullptr){ // keep looking until end of list
if(temp->data->name == name){ // found node with name
temp->data->setAge(newAge); // update the found node
return; // done searching. Exit function
}else{
temp = temp->next;
}
}
}
关于c++ - UpdateByValue函数什么都不做?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/49203800/