SDE - 1

Given a string 'S' of length 'L', return the length of the longest substring without repeating characters.

Example:

Suppose given input is "abacb", then the length of the longest substring without repeating characters will be 3 ("acb").

Stack is a data structure that follows the LIFO (Last in First out) principle. Design and implement a stack to implement the following functions:

1. Push(num): Push the given number in the stack if the stack is not full.

2. Pop: Remove and print the top element from the stack if present, else print -1.

3. Top: Print the top element of the stack if present, else print -1.

4. isEmpty: Print 1 if the stack is empty, else print 0.

5. isFull: Print 1 if the stack is full, else print 0.

You have been given ‘m’ operations which you need to perform in the stack. Your task is to implement all the functions of the stack.

Example:

We perform the following operations on an empty stack which has capacity 2:

When operation 1 1 is performed, we insert 1 in the stack.

When operation 1 2  is performed, we insert 2 in the stack. 

When operation 2 is performed, we remove the top element from the stack and print 2.

When operation 3 is performed, we print the top element of the stack, i.e., 3.

When operation 4 is performed, we print 0 because the stack is not empty.

When operation 5 is performed, we print 0 because the stack is size 1, which is not equal to its capacity.

You are given a string S of words. Your task is to find the number of palindrome words in the given string S. A word is called palindrome, if it reads the same backwards as forwards.

Note:

Words are separated by one or more whitespace characters.

For Example:

For the given string “Madam oyo cat”, “Madam”, and “oyo” are the palindrome words 

You are given an array/list ARR consisting of N integers. Your task is to find all the distinct triplets present in the array which adds up to a given number K.

An array is said to have a triplet {ARR[i], ARR[j], ARR[k]} with sum = 'K' if there exists three indices i, j and k such that i!=j, j!=k and i!=j and ARR[i] + ARR[j] + ARR[k] = 'K'.

Note:

1. You can return the list of values in any order. For example, if a valid triplet is {1, 2, -3}, then {2, -3, 1}, {-3, 2, 1} etc is also valid triplet. Also, the ordering of different triplets can be random i.e if there are more than one valid triplets, you can return them in any order.
2. The elements in the array need not be distinct.
3. If no such triplet is present in the array, then return an empty list, and the output printed for such a test case will be "-1".

Given a binary tree with ‘root’. Your task is to find the sum of all the left leaf nodes.

Properties of leaf:-

In a binary tree, a leaf is a node such that it does not have any children. Node ‘1’ is always the root of the binary tree. Left leaves are those nodes that are the left child of their parent and a leaf node.

Example:

Let’s say you have a binary tree as follows:-

Node 4 and Node 5 are leaf nodes and left child of their parent. Node 6 is a leaf node but not the left child of its parent node 3. Therefore return ‘4+5= 9’ as the answer.

Note:

You do not need to print anything; it has already been taken care of. Just implement the function.

You are given two strings 'A' and 'B' of words. Your task is to find out the most frequent and lexicographically smallest word in string 'A', which is not present in string 'B'. If no such word is present in 'A', then return -1.

Note:

1. A word is a sequence of one or more lowercase characters.

2. Words are separated by a single whitespace character.

Example:

For the given string 'A' = “coding ninjas coding ninjas” and 'B' = “data structures and algorithms”, so both the word 'coding' and 'ninjas' are not present in string 'B' and occur two times each, but the word “coding” is lexicographically smaller than the word “ninjas”. So the answer is “coding”.