Linked List Problems

[Ronaldo95163]

Hey all. I've been playing around with link lists to learn it on my own so I decided to write a small program with it that just takes in data for two nodes and display them.

#include<iostream>


using namespace std;


struct batsman{
    string name;
    int fours;
    int sixes;
    int innings;
    batsman*ptr;
    batsman();
    int aggregate();
};


batsman::batsman(){
    name = "\0";
    fours = 0;
    sixes = 0;
    innings = 0;
    
}


int batsman::aggregate(){
    return (4*fours)+(6*sixes);
}


void display(batsman*);
batsman*insert(batsman*,string,int,int);


int main(){
    batsman *topptr = NULL,*temp=NULL;
    int x,f,s;
    string name;
    for(x=1;x<=2;x++){
       cout<<"Name:";
       cin>>name;
       cin.get();
       cout<<"Fours:";
       cin>>f;
       cout<<"Sixes:";
       cin>>s;
       cin.get();
       temp = insert(topptr,name,f,s);
       cout<<endl<<endl;
    }
   
        display(temp);


    
  
    cin.get();
    return 0;  
}




batsman* insert(batsman*topptr,string name,int fours, int sixes){
    batsman*node;
    node = (batsman*)malloc(sizeof(batsman));
    if(node!=NULL){
        node->name = name;
        node->fours = fours;
        node->sixes = sixes;
        node->innings = node->aggregate();
        node->ptr = topptr;
        topptr = node;
        return topptr;
    }else{
        cout<<"Memory Not Available";
    } 


}




void display(batsman*topptr){


    while(topptr!=NULL){
        cout<<"Name:\t\t"<<topptr->name<<endl;
        cout<<"Fours:\t\t"<<topptr->fours<<endl;
        cout<<"Sixes:\t\t"<<topptr->sixes<<endl;
        cout<<"Aggregate Score:"<<topptr->innings<<endl;
        topptr = topptr->ptr;
    }
    
    
}

However as it is...only the lastly entered node displays which makes sense because as it is the link list operates as a stack...but why doesn't it go on to print the first node even though within the while loop of the display function i've incremented topptr by doing topptr=topptr->ptr?

[algorism]

It looks like you just need to use topptr everywhere you use temp (and get rid of temp).

You're missing some headers. At least <string> and something to define NULL (like cstdlib or perhaps cstddef), although in modern C++ nullptr is used instead (this requires at least C++11).

Also, "\0" is probably not what you want. "" alone adds a nul char after the (empty) string, just like "hello" adds a nul char after the final 'o'. Actually, you don't need that line at all since a string object is automatically initialized to an empty string.

And in insert the line topptr = node has no useful effect since topptr is a local variable (it doesn't modify the variable in the calling function). Just return node.

This is C code:

node = (batsman*)malloc(sizeof(batsman));

In C++ it's:

batsman* node = new batsman;

[Ronaldo95163]

Thanks lol funny thing is the answer came to me yesterday morning when I woke up and I got it working haha. For some reason it didn't occur to me at the time that I wasn't passing the updated value of the head node each time through the function.

Thanks man