How to access the object array in c++? [closed] - c++

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I am new to programming. My goal is to realize the pancake sort in C++ without using STL. I have 3 classes, they are pancake, pancakepile and MpancakePiles. I have a question about the access to the object array. My code is as following:
My pancake pile is a 3D pile and Z is it's height.
So for a single pancake pile, it has Z pancakes.
I need to find the max size's index of these Z pancakes.
However, I don't know how to access the object array, like what should I fill in the ??? area if I want to process the object array size inside the pancake P. Max is a defined function.
There is no particular reason for not using STL. N is a static size, N=512. burnt=0 means burnt side face down.
int Max(int size[], int n)
{
int mi,i;
for(mi=0,i=0;i<n;i++)
if(size[i]> size[mi])
mi=i;
return mi;
}
class pancake
{
public:
int size;
bool burnt;
void flip_pancake()
{
burnt=~burnt;
}
};
class pancakepile
{
public:
pancake P[N];
int Z;
void pan_sort_ascending()
{
int mi=Max(???,Z);
......
}
}

Answer 1

You throw away your current implementation of pan_sort_ascending, and replace it with a call to std::sort, passing a function that describes which of two pancakes should go below the other.
#include <algorithm>
// A pancake is smaller than another if it's size is less
bool pancake_less(const pancake & lhs, const pancake & rhs)
{
return lhs.size < rhs.size;
}
// sorts smallest first
void pancakepile::pan_sort_ascending()
{
std::sort(P, P + Z, pancake_less);
}
Now if you want a pan_sort_descending, you can just flip the logic of the comparison
// A pancake is larger than another if it's size is greater
bool pancake_greater(const pancake & lhs, const pancake & rhs)
{
return lhs.size > rhs.size;
}
// sorts largest first
void pancakepile::pan_sort_descending()
{
std::sort(P, P + Z, pancake_greater);
}

Answer 2

I am not sure what you want but If you only want to return the bigest pancake of the pancake list I would implement a memberfunction in the pancakepile class:
class pancakepile
{
public:
pancake P[N];
int Z;
void pan_sort_ascending()
{
int mi=max();
......
}
pancake max()
{
pancake bigestPancake;
foreach(pancake pan, P)
{
if(bigestPancake.Z < pan.Z)
bigestPancake = pan;
}
return bigestPancake;
}
}
Edit:
If you want to get the Index of the bigestPancake you can do this instead:
class pancakepile
{
public:
pancake P[N];
int Z;
void pan_sort_ascending()
{
int mi=max();
......
}
int max()
{
int bigestPancakeIndex;
for(int i = 0; i < P.size(); i++)
{
if(P[bigestPancakeIndex].Z < P[i].Z)
bigestPancakeIndex= i
}
return bigestPancakeIndex;
}
}