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#include <iostream>
#include <cstring>
template <class T>
class StackElem {
T data;
StackElem* next;
public:
StackElem(T data) : StackElem(data, nullptr) {}
StackElem(T data, StackElem* se) : data(data), next(se) {}
~StackElem() = default;
StackElem(StackElem& other) = delete;
StackElem& operator=(StackElem& other) = delete;
const T& get_data() { return this->data; }
StackElem* get_next() { return this->next; }
void set_next(StackElem* next) { this->next = next; }
};
template <class T>
class Stack {
StackElem<T>* topPtr;
StackElem<T>* startPtr;
public:
Stack() : topPtr(), startPtr() {}
Stack(Stack& other) = delete;
~Stack() {
StackElem<T>* temp;
while (startPtr != nullptr) {
temp = startPtr->get_next();
delete startPtr;
startPtr = temp;
}
}
Stack& operator=(Stack& other) = delete;
void push(T value) {
if (topPtr == nullptr)
startPtr = topPtr = new StackElem<T>(value);
else {
topPtr->set_next(new StackElem<T>(value));
topPtr = topPtr->get_next();
}
}
T pop() {
if (topPtr == nullptr) return T();
T temp = topPtr->get_data();
if (startPtr == topPtr) {
delete topPtr;
startPtr = topPtr = nullptr;
return temp;
}
StackElem<T>* prevDel = startPtr;
while (prevDel->get_next() != topPtr)
prevDel = prevDel->get_next();
delete topPtr;
topPtr = prevDel;
prevDel->set_next(nullptr);
return temp;
}
T top() {
if (topPtr == nullptr) return T();
return topPtr->get_data();
}
};
// Exercise 1
void ex1() {
const char* str = "thi*s i*s exampl*e";
unsigned strLen = strlen(str);
Stack<char> parsedStr;
for (unsigned i = 0; i < strLen; i++) {
if (str[i] == '*') parsedStr.pop();
else parsedStr.push(str[i]);
}
while (parsedStr.top() != char())
std::cout << parsedStr.pop();
std::cout << std::endl;
}
// Exercise 2
void ex2() {
const char* str = "()()(())";
unsigned strLen = strlen(str);
Stack<char> brackets;
for (unsigned i = 0; i < strLen; i++) {
if (str[i] == '(') brackets.push('(');
else if (str[i] == ')') brackets.pop();
}
if (brackets.top() != '(')
std::cout << "Balanced" << std::endl;
else
std::cout << "Unbalanced" << std::endl;
}
// Exercise 3
void ex3() {
const char* str = "1 2 - 3 + 10 *";
Stack<int> calc;
while (*str != '\0') {
if (*str >= '0' && *str <= '9') {
calc.push(atoi(str));
while (*str >= '0' && *str <= '9')
str++;
}
else if (*str == '+')
calc.push(calc.pop() + calc.pop());
else if (*str == '-')
calc.push(calc.pop() - calc.pop());
else if (*str == '*')
calc.push(calc.pop() * calc.pop());
else if (*str == '/')
calc.push(calc.pop() / calc.pop());
else if (*str == '%')
calc.push(calc.pop() % calc.pop());
str++;
}
std::cout << calc.top() << std::endl;
}
int main() {
ex3();
}
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