在排序後向鏈接列表添加數據

Question

我正在嘗試讀取文本文件，按照文本文件中的編號對每個用戶進行排序，然後將其添加到鏈接列表中。然後再次顯示它，以尊重每個節點的用戶編號按降序排列。我試圖添加編輯功能，如刪除或更新內容。

txt文件就像

John Doe; 10

Sally Tully; 5

James Watson; 12

我已經實現的是：

list.h：

#include<string> 
#ifndef LIST_H 
#define LIST_H 
class list{ 
private: 
    struct node{ 
     std::string data; 
     node* next; 
    }; 
    typedef struct node* nodePtr; 
    nodePtr head; 
    nodePtr curr; 
    nodePtr temp; 
public: 
    list(); 
    void AddNode(std::string addData); 
    void DeleteNode(std::string delData); 
    void PrintList(); 
}; 
#endif 

list.cpp

#include <cstdlib> 
#include <iostream> 
#include "list.h" 
using namespace std; 
list::list(){ //constructor 
    head = NULL; 
    curr= NULL; 
    temp=NULL; 
} 
    void list::AddNode(string addData){ 
    nodePtr n = new node; //nodePtr is node* 
    n->next=NULL; //find node n is pointing to, access its next element make it point to null 
    n->data= addData; 
    if(head != NULL) { // if we have at least 1 element in the list . 
    curr = head; // take the current pointer we are working with and make it same with head pointer pointing to.(current= front of list) 
    while(curr->next !=NULL){ // are we at the end of the list. 
    curr = curr->next;//we are not end of the list.curr pointer points next node. 
    } 
    curr->next = n; 
    }else{ //if we dont have at least 1 element in the list. 
     head =n; 
    } 
} 

void list::DeleteNode(string delData){ 
    nodePtr delPtr = NULL; 
    temp = head; 
    curr = head; 
    while(curr != NULL && curr->data != delData){ // look for data user wants to delete 
    temp = curr; 
    curr = curr->next; 
    } 
    if(curr == NULL){ // we cant find we are looking for. 
    cout << delData << "not in list"<<endl; 
    delete delPtr; 
    }else{ // we found it 
     delPtr = curr; 
     curr = curr->next; // with those 2 lines we are patching the hole in the list. 
     temp->next = curr; 
     if(delPtr == head){ 
     head = head->next; 
     temp = NULL; 
     } 
     delete delPtr; 
     cout<<delData<<"deleted"<<endl; 
    } 
} 

void list::PrintList(){ 
    curr = head; 
    while(curr !=NULL){ 
     cout<<curr->data<<endl; 
     curr = curr->next; 
    } 
} 

int main(){ 
    list mylist; 
    mylist.AddNode("hello"); 
    mylist.AddNode("how u doin"); 
    mylist.AddNode("good"); 
    mylist.PrintList(); 
    return 0; 
} 

閱讀txt文件，我應該把它們放在一個載體後（或者直接列表）然後排序然後放到鏈接列表中？我想它錯了，我應該把它們直接放在屏幕上打印之前進行排序。我也沒有任何想法如何通過用戶輸入功能來更新節點。

更新： 我實現了從txt文件向鏈接列表添加內容。

string file; 
    ifstream filein; 


    cout << "Enter file name:"<<endl; 

    cin >> file; 

    filein.open(file); 
    for(;filein.fail();) 
    { 
     cout << "Cannot open the file"<<endl; 
     cout << "Enter file name:"<<endl; 

     cin >> file; 

     filein.open(file); 
    } 

     string cline; 
     string cname; 
     string csurname; 
     int money; 
     string smoney; 
     string lastdata; 
     char delimiter=';'; 

     while (std::getline(filein, cline)){ 
       std::istringstream iss(cline); 

       while(iss >> cname >> csurname >> delimiter >> money){ 


        ostringstream temp; // int to string 
        temp<<money; 
        smoney=temp.str(); 

        lastdata = cname+" "+csurname+" "+smoney; 
        mylist.AddNode(lastdata); 







       } 







     } 

     mylist.PrintList(); 

現在它增加了像 李四10 薩莉·塔利5 問題是IM要去如何到達這個10並進行排序，同時在屏幕上打印

Answer 1

一種方式Ø解決的問題是創建兩個一種處理比較的方法和一種對鏈表進行排序的方法。

下面的方法處理比較。在這種情況下，它比較字符串的長度，但它可能是任何東西。

bool list::IsGreater(nodePtr a, nodePtr b) 
{ 
    if (a->data.length() > b->data.length()) 
     return true; 
    return false; 
} 

第二種方法對鏈表進行排序。即使有排序方法，最簡單的方法是在方法AddNode中保持列表排序。

void list::SortList() { 
    for (nodePtr i = head; i != NULL; i = i->next) { 
     nodePtr prev = NULL; 
     for (nodePtr j = head; j != NULL && j->next != NULL; j = j->next) { 
     if (IsGreater(j, j->next)) { 
      if (prev) 
       prev->next = j->next; 
      else 
       head = j->next; 

      nodePtr tmp = j->next; 
      j->next = j->next->next; 
      tmp->next = j; 
      j = tmp; 
     } 

     if (prev == NULL) 
      prev = head; 
     else 
      prev = j; 
     } 

     prev = i; 
    } 
}