SYBCom(CA) DS Practical Slip 17 Q.A

Write a C program to reverse each word of the string by using static and dynamic Implementation of stack. Example: Input – This is an input string .Output – sihTsinatupnignirts

Static Stack Implementation (Using Array)

#include <stdio.h>
#include <string.h>

#define MAX 100

// Stack structure
typedef struct {
    char arr[MAX];
    int top;
} Stack;

// Initialize stack
void init(Stack *s) {
    s->top = -1;
}

// Push operation
void push(Stack *s, char c) {
    if (s->top < MAX - 1) {
        s->arr[++(s->top)] = c;
    }
}

// Pop operation
char pop(Stack *s) {
    if (s->top >= 0) {
        return s->arr[(s->top)--];
    }
    return '\0';
}

// Check if stack is empty
int isEmpty(Stack *s) {
    return s->top == -1;
}

int main() {
    char str[MAX];
    Stack s;
    init(&s);

    printf("Enter a string: ");
    fgets(str, MAX, stdin);

    for (int i = 0; i < strlen(str); i++) {
        if (str[i] != ' ' && str[i] != '\n') {
            push(&s, str[i]);
        } else {
            while (!isEmpty(&s)) {
                printf("%c", pop(&s));
            }
            printf("%c", str[i]);
        }
    }

    // Print remaining characters
    while (!isEmpty(&s)) {
        printf("%c", pop(&s));
    }

    return 0;
}

Dynamic Stack Implementation (Using Linked List)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX 100

// Node structure
typedef struct Node {
    char data;
    struct Node* next;
} Node;

// Push operation
void push(Node** top, char c) {
    Node* newNode = (Node*)malloc(sizeof(Node));
    newNode->data = c;
    newNode->next = *top;
    *top = newNode;
}

// Pop operation
char pop(Node** top) {
    if (*top == NULL)
        return '\0';

    Node* temp = *top;
    char popped = temp->data;
    *top = temp->next;
    free(temp);
    return popped;
}

// Check if empty
int isEmpty(Node* top) {
    return top == NULL;
}

int main() {
    char str[MAX];
    Node* top = NULL;

    printf("Enter a string: ");
    fgets(str, MAX, stdin);

    for (int i = 0; i < strlen(str); i++) {
        if (str[i] != ' ' && str[i] != '\n') {
            push(&top, str[i]);
        } else {
            while (!isEmpty(top)) {
                printf("%c", pop(&top));
            }
            printf("%c", str[i]);
        }
    }

    // Print remaining characters
    while (!isEmpty(top)) {
        printf("%c", pop(&top));
    }

    return 0;
}