Question

Parameter Passing:

Use the following parameter passing methods:

1) Call by reference

2) Call by value

Consider the following function: Check Sums (A,B,C) where A is a two-dimensional (2D) array of size [1:n, 1:n) and B and Care vectors of size [1:n), n being a positive integer. The body of CheckSums implements the following computations: B[i] = A[1,1] - A[1,2] + A[i,3] - .... A[i,n] C[i] = A[1,i] - A[2,i] + A[3,i] - .... A[n,i]. a. Give the complete function CheckSums (A,B,C), including the code of the function body and the method of passing the three parameters. b. Determine the time and space complexity of your function (space complexity is the amount of memory space required by the function, in addition to the space for the actual parameters). Warning: Your function must work correctly for calls such as CheckSums (D[1:n, 1:n), D[1:n, 1], D[1,1:n])! where D[1:n,1] is the first column of the 2D array D and D[1,1:n) is the first row.

Answer 1

// PassByValueCode.cpp

#include <iostream>
#include <array>
using namespace std ;

int CheckSums( array<int, 10> A, array<int, 10> B, array<int, 10> C)
{
   array <int, 10> arrD;
   int value = 0;
  
   for(int i = 0; i < 10 ; i++){
       arrD[i] = A[i]^B[i]^C[i];
   }
  
   for(int i = 0; i < 10; i++){
       value = value ^ arrD[i];
   }
   return value;
}

int main()
{
   array <int, 10> arrA = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 };
   array <int, 10> arrB = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 };
   array <int, 10> arrC = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 };

   CheckSums(arrA ,arrB, arrC);
   return 0;
}

// PassByRefCode.cpp

#include <iostream>
#include <array>
using namespace std ;

int CheckSums( int * A, int* B, int *C )
{
   int arrD[10];
   int value = 0;
  
   for(int i = 0; i < 10 ; i++){
       arrD[i] = A[i]^B[i]^C[i];
   }
  
   for(int i = 0; i < 10; i++){
       value = value ^ arrD[i];
   }
   return value;
  
}

int main()
{
   int arrA[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 };
   int arrB[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 };
   int arrC[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 };

   CheckSums(arrA ,arrB, arrC);
   return 0;
}

// Below is memory comparison with Linux OS x86 System

PassByValueCode : 17136 Byte
PassByValueRef :   17000 Bytes

// Below is execution time comparions:

PassByValueCode : 11 ms
PassByValueRef : 8 ms