cs-fedy

class ListStack:
    def __init__(self):
        self.stack = []

    def is_empty(self):
        return not self.stack

    def get_peek(self):
        assert(not self.is_empty())
        return self.stack[-1]

cs-fedy

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

struct stack {
    int * keys;
    int max_size;
    int peek;
};

cs-fedy

class Node:
    def __init__(self, key):
        self.key = key
        self.next = None

class Stack:
    def __init__(self):
        self.peek = None
    
    def is_empty(self):

cs-fedy

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

struct node {
    int key;
    struct node * next;
};

//Function prototpye or method on stack.

cs-fedy

// Write code to efficiently evaluate given postfix expression.
int evaluate_exp(char exp[], stck * st) {
    int index = 0, x, y;
    char ch;
    while (exp[index] != '\0') {
        ch = exp[index];
        if (ch >= '0' && ch <= '9') {
            push(ch - '0', st);
        }
        else {

cs-fedy

// Given a balanced expression that can contain opening and closing parenthesis, 
// check if the expression contains any duplicate parenthesis or not.
unsigned is_duplicated(char str[], stck * st) {
    int index = 0;
    char ch;
    while (str[index] != '\0') {
        ch = str[index]; 
        if (ch != ')') 
            push(ch, st);
        else {

cs-fedy

// Given a string containing opening and closing braces, 
// check if it represents a balanced expression or not.
unsigned is_balanced(char str[], stck * st) {
    int index = 0; 
    char top, ch;
    while(str[index] != '\0') {
        ch = str[index];
        if (ch == '{' || ch == '(' || ch == '[') {
            push(ch, st);
        }

cs-fedy

class Node:
    def __init__(self, key):
        self.key = key
        self.next = None
        self.prev = None

class CircularLinkedList:
    def __init__(self):
        self.head = None

cs-fedy

class Node:
    def __init__(self, key):
        self.key = key
        self.next = None
        self.prev = None

class DoublyLinkedList:
    def __init__(self):
        self.head = None

cs-fedy

class Node:
    def __init__(self, key):
        self.key = key
        self.next = None


class LinkedList:
    def __init__(self):
        self.head = None