Thread: Need Help On an Assignment

@laserlight

Well...str is the variable that's being put into contents. FrontStr takes the contents and adds it to the array. If I got rid of FrontStr and replaced it with str, what would go into contents?

@jiggunjer

I'm very new with delete and not sure what's wrong with it or what a one line code would be in this case. As for copy, I have never successfully used that before at all, so what's wrong with the syntax exactly?

For size, I think I fixed it...

Code:

void IncreaseCapacity() {
  arraysize += 10;
  std::string* newarray = new std::string[arraysize];
  myarray[arraysize];
  myarray.copy(newarray);
  while (i < arraysize) {
    delete [] myarray[i];
    myarray[i] = NULL;
    ++i;
  }
  delete [] myarray;
  myarray = NULL;
  std::swap(myarray, newarray); 
}

Size declared, size implemented into new array, size also implemented into old array. Is that right?

Yeah now you can just do:

Code:

void IncreaseCapacity() 
{
   // Make a new, bigger array:
   const int oldsize = arraysize;
   arraysize += 10;
   std::string* newarray = new std::string[arraysize];

   // Do the copy:
   for (int i = 0; i < oldsize; i++) {
      newarray[i] = myarray[i];
   }

   // Swap the old and new arrays:
   delete [] myarray;
   myarray = NULL;
   std::swap(myarray, newarray);
}

So using this, AddFront and AddBack would be fine? Also, thanks for the notes, they really help me understand what's going on with the code. Thanks! =)

Ahhh, right, so something like this?

Code:

int i = myarray;

int j = contents;

int k = arraysize;

if (i + j > k) { }

myarray is a pointer, not an int.
contents is a string, not an int.
arraysize is the capacity, not the actual occupied size
In short: your if statement makes no sense. In my header example I made a clear distinction between N and NNZ.
Your if should look like

Code:

if(NNZ==N){increasesize()}

BackAdd should add the string to the array while keeping the elements continuous. For example
before: xxx... (3 strings in array of size 6)
after: xxxx..(4 strings in array of size 6)
currently your after is: xxx..x (non-continuous appending).

P.S no need for a new keyword in BackAdd.

Hi,I have a question in below code.
in tower function in else, do act all of statement ?(I cant speak English well,sorry).
Tanks

Code:

Code:

#include <stdio.h>
#include <conio.h>
#include <iostream>
 
void tower(int,char,char,char);
int main()
{
int ndisk;
system("cls");
printf("\nEnter number of disks : ");
scanf("%d",&ndisk);
tower(ndisk,'A','B','C');
getch();
return 0;
}//end of main()
 
void tower(int topN, char src,char aux,char dest)
{
if(topN == 1)
{
printf("\n Disk 1 from %c to %c ",src,dest);
}
else
{
tower(topN-1,src,dest,aux); //src to aux
printf("\n Disk %d from %c to %c ",topN,src,dest);
tower(topN-1,aux,src,dest); //aux to dest
}
}//end of tower()

Oh! I goofed, for some reason I was thinking myarray would also give the size. ^^;

Code:

if(NNZ==N){increasesize()}

What I don't get is why you have an equal sign for this. Isn't the point to increase the size if it's larger? Or at the very least have it set to >= for greater than or equal to? Or did I miss something?

And for AddBack, would doing a double swap solve this problem or would it still be the same?

When the array is full, both would be 10, but when I need to increase it, size would be over 10, no?

Alright well this is what I have for AddFront.

Code:

void AddFront(std::string str) {
  std::string FrontStr;
  std::string contents(str);
  currentsize = sizeof myarray;
  if(currentsize == arraysize) {
    IncreaseCapacity();
  }
  contents.copy(FrontStr, arraysize);
  std::swap(myarray[i], FrontStr);
}

currentsize is the private int for the currentarray size, but I'm not 100% sure if I did it properly.