c++ - Deleting nodes that are outside of a specific numeric range in a singly linked list -

i working on program reads text file , grabs data out of text file , inserts nodes of linked list.

i have whole program running , working fine besides node deletion. filtering data text file need print out data have values within range. can if() statement , works fine that's not result want.

i want delete nodes outside of specified range , free memory using. have few lines of code wrote try ends deleting entire list. if point me in right direction , tell me i'm doing wrong great!

#include <fstream> #include <iostream> using namespace std;  struct employee {     string firstn;     string lastn;     float salary;     float bonus;     float deduction;      employee *link; };  typedef employee* employptr; void insertathead( employptr&, string, string, float, float,float ); void insert( employptr&, string, string, float, float,float ); float netsalary( employptr& );  int main() { //open file fstream in( "payroll.txt", ios::in );  //read lines string first, last; float salary, bonus, deduction; employptr head = new employee;  //inserts data new node in linked list, creating new node each time loop executes. while( in >> first >> last >> salary >> bonus >> deduction)     insertathead (head, first, last, salary, bonus, deduction);  //close file in.close();  cout << "-salary in range of ($45,000 - $60,000)-\n" << "printed in format: first name, last name, salary, bonus, deduction, net salary.\n";  employptr iter, temp; for(iter = head; iter!= null; iter = iter->link) {     temp = head;     //deletes nodes outside of range.     while(netsalary(iter)<45000 || netsalary(iter)>60000)     {         employptr nodetodelete = temp;         temp = temp->link;         delete nodetodelete;     }      cout << iter->firstn << ", " << iter->lastn << ", " << iter->salary << ", " << iter->bonus << ", " << iter->deduction << ", " << netsalary(iter) <<endl;  }     return 0; }      //based off of input values, function create new node , insert @ beginning of linked list. function allows insertion @ beginning of list , no else.  void insertathead(employptr& head, string firstvalue, string lastvalue,             float salaryvalue, float bonusvalue,float deductionvalue) {     employptr tempptr= new employee;      tempptr->firstn = firstvalue;     tempptr->lastn = lastvalue;     tempptr->salary = salaryvalue;     tempptr->bonus = bonusvalue;     tempptr->deduction = deductionvalue;      tempptr->link = head;     head = tempptr; }  //based off of input values, function creates new node , inserts after node provided in argument. void insert(employptr& afternode, string firstvalue, string lastvalue,         float salaryvalue, float bonusvalue,float deductionvalue) {     employptr tempptr= new employee;       tempptr->firstn = firstvalue;     tempptr->lastn = lastvalue;     tempptr->salary = salaryvalue;     tempptr->bonus = bonusvalue;     tempptr->deduction = deductionvalue;      tempptr->link = afternode->link;     afternode->link = tempptr; }  //this function calculates net salary based off of salary, bonus, , deduction variables of input node. float netsalary(employptr& node) {     float netsalary, newdeduction;      newdeduction = ((node->salary) + (node->bonus)) * (node->deduction);     netsalary = (node->salary + node->bonus) - newdeduction;      return netsalary; } 

edit: changed && || still having issue.

edit #2: solution

while(netsalary(iter)<45000 || netsalary(iter)>60000)         {             employptr nodetodelete = new employee;             nodetodelete = iter;             iter = iter->link;             delete nodetodelete;         } 

this line right here:

while(netsalary(iter)<45000 && netsalary(iter)>60000) 

i believe conditional should or (||). not make sense value both less 45000 , more 60000 @ same time.

given value 25000, less 45000, not more 60000, therefore nothing ever deleted.

edit: perhaps try along these lines:

for (iter = head; iter != null; iter = iter->link)  {     cout << iter->salary; // can see node it's looking @     if (netsalary(iter) < 45000 || netsalary(iter) > 60000)     {         employptr nodetodelete = iter;         iter = iter->link; // difference here you're explicitly moving iter forward         delete nodetodelete;     }  }