Mergesort C++ Windows Form Application - c++

Question

I am at work on a gui based mergesort application. I am trying to print the steps as the recursive mergesort moves along. I am having trouble with accessing the "richTextBox1" component within my mergesort/print_arr() so I can print the current array out to the window. I am getting these errors which I understand a little bit. I think it has to do merge_sort being a static method trying to access a class component. I am stumped, any suggestions or workarounds for this without having to start completely over?
Here are the errors:
Form1.h(185): error C2227: left of '->Text' must point to class/struct/union/generic type
Form1.h(187): error C2227: left of '->Text' must point to class/struct/union/generic type
Form1.h(189): error C2227: left of '->Text' must point to class/struct/union/generic type
These errors are coming from the print_arr(arr[],size) method.
and the code......
#pragma once
#include <iostream>
#include <time.h>
#include <msclr\marshal.h>
#include <msclr\marshal_cppstd.h>
namespace prog1 {
using namespace std;
using namespace System;
using namespace System::ComponentModel;
using namespace System::Collections;
using namespace System::Windows::Forms;
using namespace System::Data;
using namespace System::Drawing;
using namespace msclr::interop;
/// <summary>
/// Summary for Form1
/// </summary>
public ref class Form1 : public System::Windows::Forms::Form
{
public:
Form1(void)
{
InitializeComponent();
//
//TODO: Add the constructor code here
//
}
static void randomize(int* a, int size){
srand ( time(NULL) );
for(unsigned i = 0; i < size; i++){
a[i] = rand()%45 + 1;
}
for(unsigned i = 0; i < size; i++){
cout << a[i] << " ";
}
}
protected:
/// <summary>
/// Clean up any resources being used.
/// </summary>
~Form1()
{
if (components)
{
delete components;
}
}
private: System::Windows::Forms::Label^ label1;
protected:
private: System::Windows::Forms::TextBox^ textBox1;
private: System::Windows::Forms::Button^ randButton;
private: System::Windows::Forms::Button^ increaseButton;
private: System::Windows::Forms::Button^ decreaseButton;
private: System::Windows::Forms::Label^ label2;
private: System::Windows::Forms::RichTextBox^ richTextBox1;
private: System::Windows::Forms::Button^ clearButton;
private:
/// <summary>
/// Required designer variable.
/// </summary>
System::ComponentModel::Container ^components;
#pragma region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
void InitializeComponent(void)
{
this->label1 = (gcnew System::Windows::Forms::Label());
this->textBox1 = (gcnew System::Windows::Forms::TextBox());
this->randButton = (gcnew System::Windows::Forms::Button());
this->increaseButton = (gcnew System::Windows::Forms::Button());
this->decreaseButton = (gcnew System::Windows::Forms::Button());
this->label2 = (gcnew System::Windows::Forms::Label());
this->richTextBox1 = (gcnew System::Windows::Forms::RichTextBox());
this->clearButton = (gcnew System::Windows::Forms::Button());
this->SuspendLayout();
//
// label1
//
this->label1->AutoSize = true;
this->label1->Location = System::Drawing::Point(13, 13);
this->label1->Name = L"label1";
this->label1->Size = System::Drawing::Size(65, 13);
this->label1->TabIndex = 0;
this->label1->Text = L"Enter a size:";
//
// textBox1
//
this->textBox1->Location = System::Drawing::Point(84, 13);
this->textBox1->Name = L"textBox1";
this->textBox1->Size = System::Drawing::Size(27, 20);
this->textBox1->TabIndex = 1;
//
// randButton
//
this->randButton->Location = System::Drawing::Point(118, 9);
this->randButton->Name = L"randButton";
this->randButton->Size = System::Drawing::Size(75, 23);
this->randButton->TabIndex = 2;
this->randButton->Text = L"Random";
this->randButton->UseVisualStyleBackColor = true;
this->randButton->Click += gcnew System::EventHandler(this, &Form1::randButton_Click);
//
// increaseButton
//
this->increaseButton->Location = System::Drawing::Point(200, 9);
this->increaseButton->Name = L"increaseButton";
this->increaseButton->Size = System::Drawing::Size(75, 23);
this->increaseButton->TabIndex = 3;
this->increaseButton->Text = L"Increasing";
this->increaseButton->UseVisualStyleBackColor = true;
//
// decreaseButton
//
this->decreaseButton->Location = System::Drawing::Point(282, 9);
this->decreaseButton->Name = L"decreaseButton";
this->decreaseButton->Size = System::Drawing::Size(75, 23);
this->decreaseButton->TabIndex = 4;
this->decreaseButton->Text = L"Decreasing";
this->decreaseButton->UseVisualStyleBackColor = true;
//
// label2
//
this->label2->AutoSize = true;
this->label2->Location = System::Drawing::Point(363, 14);
this->label2->Name = L"label2";
this->label2->Size = System::Drawing::Size(91, 13);
this->label2->TabIndex = 5;
this->label2->Text = L"# of comparisons:";
//
// richTextBox1
//
this->richTextBox1->Location = System::Drawing::Point(16, 44);
this->richTextBox1->Name = L"richTextBox1";
this->richTextBox1->Size = System::Drawing::Size(473, 238);
this->richTextBox1->TabIndex = 6;
this->richTextBox1->Text = L"";
//
// clearButton
//
this->clearButton->Location = System::Drawing::Point(411, 289);
this->clearButton->Name = L"clearButton";
this->clearButton->Size = System::Drawing::Size(75, 23);
this->clearButton->TabIndex = 7;
this->clearButton->Text = L"Clear";
this->clearButton->UseVisualStyleBackColor = true;
//
// Form1
//
this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
this->ClientSize = System::Drawing::Size(501, 319);
this->Controls->Add(this->clearButton);
this->Controls->Add(this->richTextBox1);
this->Controls->Add(this->label2);
this->Controls->Add(this->decreaseButton);
this->Controls->Add(this->increaseButton);
this->Controls->Add(this->randButton);
this->Controls->Add(this->textBox1);
this->Controls->Add(this->label1);
this->Name = L"Form1";
this->Text = L"CS4413 MergeSort";
this->ResumeLayout(false);
this->PerformLayout();
}
#pragma endregion
static void print_arr(int* arr, int size){
richTextBox1->Text = "[ ";
for(int i = 0; i < size; i++){
richTextBox1->Text = arr[i] + ", ";
}
richTextBox1->Text = " ]";
}
static void merge_arrays(int h, int m, int arr[], int arrA[], int arrB[]){
int i = 0,j=0,k=0;
while(i < h && j < m){
if(arrA[i] < arrB[j]){
arr[k] = arrA[i];
i++;
}else{
arr[k] = arrB[j];
j++;
}
k++;
}
if(i > h){
for(int x = j; x < m; x++){
arr[k] = arrB[x];
k++;
}
}else{
for(int x = i; x < h; x++){
arr[k] = arrA[x];
k++;
}
}
}
static int* merge_sort(int* arr, const int size){
if ( size == 1 )
return arr;
int h = size/2;
int m = size/2;
int arrayAHsize = h;
int arrayBMsize = size - m;
//cout << "h: " << h << "arr[h]: " << arr[h] << "m: " << m << " arraryBMsize" <<
//arrayBMsize<< endl;
int *arrA = (int*)malloc(h);
int *arrB = (int*)malloc(arrayBMsize);
int* pa;
int* pb;
for(int i = 0; i < h; i++){
arrA[i] = arr[i];
}
for(int i = 0; i < arrayBMsize; i++){
arrB[i] = arr[i + h];
}
cout << endl;
print_arr(arrA, size/2);
cout << "----";
print_arr(arrB, arrayBMsize);
cout << endl;
//l1 = mergesort( l1 )
pa = merge_sort(arrA,h);
//l2 = mergesort( l2 )
pb = merge_sort(arrB, arrayBMsize);
merge_arrays( h, arrayBMsize,arr, arrA, arrB);
}
private: System::Void randButton_Click(System::Object^ sender, System::EventArgs^ e) {
String^ s = textBox1->Text;
string Ssize = marshal_as<std::string>(s);
const int size = atoi(Ssize.c_str());
//int a[atoi(Ssize.c_str())];
int *a = (int*)malloc(size);
int* pa = a;
//int* pa;
randomize(a, size);
richTextBox1->Text += "Your set: \n";
for(int i = 0; i < size; i++){
richTextBox1->Text += a[i] + ", ";
}
pa = merge_sort(a,size);
}
};
}

Answer 1

static void print_arr(int* arr, int size){
richTextBox1->Text = "[ ";
for(int i = 0; i < size; i++){
richTextBox1->Text = arr[i] + ", ";
}
richTextBox1->Text = " ]";
}
Is wrong because richTextBox1 is a data member of the class, and a static function cannot access a class data member. Data members are for instances of the class, and thus a static function, not having an instance, would not know which instances data members to refer to.
Make this method non-static and you'll be fine.