StringReverseUsingStack.cpp

#include <bits/stdc++.h>

using namespace std;

class Stack {
public:
    int top;
    unsigned capacity;
    char *array;
};

Stack *createStack(unsigned capacity) {
    Stack *stack = new Stack();
    stack->capacity = capacity;
    stack->top = -1;
    stack->array = new char[(stack->capacity * sizeof(char))];
    return stack;
}

int isFull(Stack *stack) { return stack->top == stack->capacity - 1; }

int isEmpty(Stack *stack) { return stack->top == -1; }

void push(Stack *stack, char item) {
    if (isFull(stack))
        return;
    stack->array[++stack->top] = item;
}

char pop(Stack *stack) {
    if (isEmpty(stack))
        return -1;
    return stack->array[stack->top--];
}

void reverse(char str[]) {
    int n = strlen(str);
    Stack *stack = createStack(n);

    int i;
    for (i = 0; i < n; i++)
        push(stack, str[i]);

    for (i = 0; i < n; i++)
        str[i] = pop(stack);
}

int main() {
    char str[] = "StringExample";

    reverse(str);
    cout << "\nReversed string is " << str;

    return 0;
}