SDE - 1

Here are 10 stacks of 10 coins each.
Each coin weights 10 gms. However, one stack of coins is defective and each coin in that stack weights only 9 gms.

What is the minimum number of weights you need to take to find which stack is defective? How?

You are given an array 'ARR' of integers of length N. Your task is to find the next smaller element for each of the array elements.

Next Smaller Element for an array element is the first element to the right of that element which has a value strictly smaller than that element.

If for any array element the next smaller element does not exist, you should print -1 for that array element.

For Example:

If the given array is [ 2, 3, 1], we need to return [1, 1, -1]. Because for  2, 1 is the Next Smaller element. For 3, 1 is the Next Smaller element and for 1, there is no next smaller element hence the answer for this element is -1.

You are given an array/list 'prices' where the elements of the array represent the prices of the stock as they were yesterday and indices of the array represent minutes. Your task is to find and return the maximum profit you can make by buying and selling the stock. You can buy and sell the stock only once.

Note:

You can’t sell without buying first.

For Example:

For the given array [ 2, 100, 150, 120],
The maximum profit can be achieved by buying the stock at minute 0 when its price is Rs. 2 and selling it at minute 2 when its price is Rs. 150.
So, the output will be 148.

You are given a string ‘expression’ consists of characters ‘+’, ‘-’, ‘*’, ‘/’, ‘(‘, ‘)’ and ‘0’ to ‘9’, that represents an Arithmetic Expression in Infix Notation. Your task is to evaluate this Arithmetic Expression.

In Infix Notation, operators are written in-between their operands.

Note :

1. We consider the ‘/’ operator as the floor division.

2. Operators ‘*’ and ‘/’ expression has higher precedence over operators‘+’ and ‘-’ 

3. String expression always starts with ‘(‘ and ends with ‘)’.

4. It is guaranteed that ‘expression’ represents’ a valid expression in Infix notation.

5. It is guaranteed that there will be no case that requires division by 0.

6. No characters other than those mentioned above are present in the string. 

7. It is guaranteed that the operands and final result will fit in a 32-bit integer.

For example :

Consider string ‘expression’ = ‘((2+3)*(5/2))’. 
Then it’s value after evaluation will be ((5)*(2)) = 10. 

What is the real life use of the projects I made?
Which technology is used for making projects and why?
Which framework is used to develop the project?
Explain the functionality of the project.

You are given a string 'S'. Your task is to check whether the string is palindrome or not. For checking palindrome, consider alphabets and numbers only and ignore the symbols and whitespaces.

Note :

String 'S' is NOT case sensitive.

Example :

Let S = “c1 O$d@eeD o1c”.
If we ignore the special characters, whitespaces and convert all uppercase letters to lowercase, we get S = “c1odeedo1c”, which is a palindrome. Hence, the given string is also a palindrome.

You are given an array “arr'' of integers. Your task is to find the contiguous subarray within the array which has the largest product of its elements. You have to report this maximum product.

An array c is a subarray of array d if c can be obtained from d by deletion of several elements from the beginning and several elements from the end.

For e.g.- The non-empty subarrays of an array [1,2,3] will be- [1],[2],[3],[1,2],[2,3],[1,2,3]. 

For Example:

If arr = {-3,4,5}.
All the possible non-empty contiguous subarrays of “arr” are {-3}, {4}, {5}, {-3,4}, {4,5} and {-3,4,5}.
The product of these subarrays are -3, 4, 5, -12, 20 and -60 respectively.
The maximum product is 20. Hence, the answer is 20.

Follow Up:

Can you solve this in linear time and constant space complexity?