How to generate a random array of integers subject to a certain constraint

Posted on 16th Feb 2014 by admin

I am writing a program that asks the user to enter an integer N and then generates a random array of integers of size 2^N, each of whose entries range from 1 to N+1. The final random array, however, must satisfy the following properties: the integer 1 can be stored in 1 slot, the integer 2 can only be stored in 1 slot, the integer 3 can only be stored in 2 slots, the integer 4 can only be stored in 4 slots... until all 2^N slots are filled with the integers 1, 2, ...,N+1.

I have written some code that asks the user to enter an integer N and then
generates a random array of integers of size 2^N but I cannot generate a random array subject to the constraints that I mentioned above. I have written a function, CheckArray, that returns the value of how many times a certain integer
appears in the array but I don't know how to use it to help me get my desired random array.

Below is the code I have written so far. Note that the function CheckArray is not called in the program since I don't know how to use it yet.

#include
#include
#include
#include
#include
using namespace std;

int RandomNumber(int m);
int exponentiation(int n);
int CheckArray(int IntegerArray[], int sizeOfArray, int CType);

int main()
{ int N;
int NUMOFCELLS;

cout<< "Enter the maximum number of cell divisions you want: ";
cin>>N;
NUMOFCELLS = exponentiation(N);
cout<<"The maximum number of cells will be: ";

cout< cout<<"n";
cout<<"n";

int sample[128]; // this reserves 128 integer elements
int t;

srand(time(0));
getchar();

for(t = 0; t <= NUMOFCELLS; t++)
{ sample[t] = RandomNumber(N); }

// display the array

for(t = 0; t < NUMOFCELLS; ++t)
{ cout << sample[t] << ' ' ; }

cout<<"n";

getchar();
return 0;
}

int RandomNumber(int m)
{ // generates a random number in the specified range from 0 to (m-1)
int iSecret;
iSecret = rand() % m + 1;
return(iSecret);
}

int exponentiation(int n)
{ int t;
int numberofcells;
numberofcells = 2;
for(t=1; t < n; ++t)
{numberofcells = 2*numberofcells;}

return(numberofcells);
}

int CheckArray(int IntegerArray[], int sizeOfArray, int CType)
{
int accumulator = 0;
int temp;

for(int i = 0; i < sizeOfArray; i++)
{ temp = IntegerArray[i];
if(temp == CType)
{accumulator++;}

}

return accumulator;
}