pointers - How can I delete a node in my linked list in C++? -

i've pasted work far here: http://codepad.org/whjuujrm

the concepts of linked lists boggle mind, thought i'd practice. know how add nodes, , edit nodes, don't know how remove nodes in particular scenario.

my pseudo code:

previous == - 1; if(stdid == now->getid()); previous->setnext(now->getnext); delete now; return; 

how implement this?

the mind-tease in deleting element linked list updating pointer brought element in first place. in list case, top (and/or possibly bottom), node's next. walk through list hunting cur pointer, keep prev pointer advance 1 step behind enumerate. assuming find victim node (if don't, there's nothing do, woot!), prev in 1 of 2 states:

• it null, in case top pointer refers victim node , top must updated, or...
• it pointer node, in case node's next member needs updated reflect victim node's next member value.

in both cases bottom may need updating well. in first case bottom need change if list had 1 node , you're deleting it. i.e. have empty list when finished. easy enough tell, since top null after detach cur , set top equal cur->next. easier you, since you're keeping size member in list container; if 1, know both head , bottom

in second case, last node may victim node. in case bottom has updated reflect new end of list (which coincidentally in prev, , may null if, once again, list had single element. how tell if victim last node in list? if it's next member null, has last node, , bottom must updated.

so this, delete function based on id search

void deletestudent(int id) {     student *cur = top, *prev = nullptr;     while (cur && cur->getid() != id)     {         prev = cur;         cur = cur->getnext();     }      // found node?     if (cur)     {         student *pnext = cur->getnext();          // set new next pointer prev, or new top         if (prev)             prev->setnext(pnext);         else             top = pnext;          // update bottom if needed         if (!pnext)             bottom = prev;          delete cur;         --scnt;     } } 

other delete options , criteria leave you.

best of luck.