Converting Decimal in String Format to a Double Using Stacks - c++

Question

this project is currently due by tonight and I have tried my best on it so far. If I could get any guidance on to how I should continue working on it that would be greatly appreciated. I have this topic I am covering for a project: "Write a program that reads a string consisting of a positive integer or a positive decimal number and converts the number to the numeric format. If the string consists of a decimal number, the program must use a stack to convert the decimal number to the numeric format."
I am first of all, confused as to how a stack would help make a decimal in string format into a decimal in numeric format. How would that work internally in the program? Second of all, my code that I created is not working for some reason and I'm unsure as to of why.
I tried looking into questions that were asked on stack overflow and other websites but nothing could answer my question.
#include <iostream>
#include <cassert>
#include <string>
using namespace std;
template <class Type>
class stackADT
{
public:
virtual void initializeStack() = 0;
virtual bool isEmptyStack() const = 0;
virtual bool isFullStack() const = 0;
virtual void push(const Type& newItem) = 0;
virtual Type top() const = 0;
virtual void pop() = 0;
};
template <class Type>
class stackType: public stackADT<Type>
{
private:
int maxStackSize;
int stackTop;
public:
Type *list;
void initializeStack()
{
stackTop = 0;
cout << "stackTop " << stackTop << endl;
}
void print()
{
for(int i=0; i<stackTop; i++)
{
cout << list[i] << endl;
}
}
bool isEmptyStack() const
{
return(stackTop == 0);
}
bool isFullStack() const
{
return(stackTop == maxStackSize);
}
void push(const Type& newItem)
{
if (!isFullStack())
{
list[stackTop] = newItem;
stackTop++;
}
else
{
cout << "Cannot add to a full stack." << endl;
}
cout << "stacktop: " << stackTop << endl;
system("pause");
}
Type top() const
{
assert(stackTop != 0); //if stack is empty, terminate the program.
return list[stackTop - 1];
}
Type getList() const
{
assert(stackTop != 0); //if stack is empty, terminate the program.
return *list;
}
void pop()
{
if (!isEmptyStack())
stackTop--;
else
cout << "Cannot remove from an empty stack." << endl;
cout << "pop: " << stackTop << endl;
}
stackType(int stackSize = 100)
{
if (stackSize <= 0)
{
cout << "Size of the array to hold the stack must be positive." << endl;
cout << "Creating an array of size 100." << endl;
maxStackSize = 100;
}
else
{
maxStackSize = stackSize;
// cout << "maxStackSize " << maxStackSize << endl;
}
stackTop = 0;
list = new Type[maxStackSize];
}
stackType(const stackType<Type>& otherStack)
{
list = NULL;
copyStack(otherStack);
}
~stackType()
{
delete [] list;
}
const stackType<Type>& operator=(const stackType<Type>& otherStack)
{
if (this != &otherStack)
{
copyStack(otherStack);
}
return *this;
}
bool operator==(const stackType<Type>& otherStack) const
{
if (this == &otherStack)
{
return true;
}
else
{
if (stackTop != otherStack.stackTop)
{
return false;
}
else
{
for (int i = 0; i < stackTop; i++)
{
if (list[i] != otherStack.list[i])
{
return false;
}
return true;
}
}
}
}
void copyStack(const stackType<Type>& otherStack)
{
delete [] list;
maxStackSize = otherStack.maxStackSize;
stackTop = otherStack.stackTop;
list = new Type[maxStackSize];
//copy otherStack into this stack.
for (int j = 0; j < stackTop; j++)
{
list[j] = otherStack.list[j];
}
}
};
int main()
{
string s;
char c;
bool found;
int b = 0;
string j = "";
stackType<double> stack;
cout<<"Would you like to convert an integer(i) or a decimal(d)?"<<endl;
cin>>c;
switch (c) {
case 'i' :
case 'I' : {
cout << "Please enter your integer in string format: ";
cin >> s;
b = atoi(s.c_str());
break;
}
case 'd' :
case 'D' : {
cout << "Please enter your decimal in string format: ";
cin >> s;
found = false;
int q = 0;
while(found == false) {
if(s[q] == '.') {
found = true;
}
else {
q++;
}
}
for (int i = 0; i <q; i++) {
char p = s[i];
j += p;
for (int m = 0; m<q-i; m++) {
j += '0';
}
double k = stof(j);
stack.push(k);
j.clear();
}
break;
}
default: {
cout <<"Wrong input. Please enter i or d for integer or decimal: ";
cin>>c;
break;
}
}
cout << "Here is your string in integer or decimal format: ";
double t = 0;
if(c == 'i') {
cout << b;
}
else if(c == 'd') {
for(int i = 0; i < stack.top(); i++){
t += stack.list[i];
}
cout << t;
}
return 0;
}
I expect the output to be the number printed out correctly as to when I entered it but the output is :
Would you like to convert an integer(i) or a decimal(d)?
d
Please enter your decimal in string format: 1025.56
stacktop: 1
sh: pause: command not found
stacktop: 2
sh: pause: command not found
stacktop: 3
sh: pause: command not found
stacktop: 4
sh: pause: command not found
Here is your string in integer or decimal format: 9.74742e+232Program ended with exit code: 0

Answer 1

Let the input string be 2345.6789. Since it is a string, its individual characters are stored in the consecutive locations in memory. Now, let's access them sequentially, and execute the following algorithm.
First, evaluate the integer part
int Acc = 0;
Loop 1: Repeat until Input == Decimal point
Input = '2'; Acc = 10 * Acc + (Input - '0') = 10 x 0 + 2 = 2
Input = '3'; Acc = 10 * Acc + (Input - '0') = 10 x 2 + 3 = 23
Input = '4'; Acc = 10 * Acc + (Input - '0') = 10 x 23 + 4 = 234
Input = '5'; Acc = 10 * Acc + (Input - '0') = 10 x 234 + 5 = 2345
Input = '.' (Decimal point); exit Loop1
Next, fill the stack with digits in the fractional part.
auto stack = std::stack<int>
Loop2: Repeat until Input == End of string
Input = '6'; stack.push (Input - '0');
Input = '7'; stack.push (Input - '0');
Input = '8'; stack.push (Input - '0');
Input = '9'; stack.push (Input - '0');
Input = End of string; exit Loop2
Next, pop digits from the stack, and evaluate the fractional part.
double Acc2 = 0;
Loop 3: repeat until stack.empty()
Acc2 = (Acc2 + stack.top()) / 10 = (0 + 9) / 10 = 0.9; stack.pop();
Acc2 = (Acc2 + stack.top()) / 10 = (0.9 + 8) / 10 = 0.89; stack.pop();
Acc2 = (Acc2 + stack.top()) / 10 = (0.89 + 7) / 10 = 0.789; stack.pop();
Acc2 = (Acc2 + stack.top()) / 10 = (0.789 + 6) / 10 = 0.6789; stack.pop();
Finally, add the integer part to the fractional part.
Result = Acc + Acc2
This is a purely academic problem. Convey my regards to your teacher.