SDE - Intern

You are given an array of integers 'ARR' of length 'N' and an integer Target. Your task is to return all pairs of elements such that they add up to Target.

Note:

We cannot use the element at a given index twice.

Follow Up:

Try to do this problem in O(N) time complexity. 

Gary has a sequence 'ARR', consisting of 'N' integers.

We'll call a sequence ARR[i],  ARR[i+1], ..., ARR[j] where 1  ≤  i  ≤  j  ≤  N a subsegment of the sequence ARR. The value (j - i + 1) denotes the length of the subsegment.

Your task is to find the longest subsegment of ARR, such that it is possible to change at most one number (change one number to any integer you want) from the subsegment to make the subsegment strictly increasing.

You need to return the length of the maximum subsegment that you can find by changing only one integer in the given sequence.

Regular Expression question: Write a regular expression that returns true if the first character of the string is the same as the last character. 

Note: The string was made from only 2 characters (a and b)

You are given an array 'ARR' of integers. Your task is to modify the array so that all the array elements having zero values get pushed to the left and all the array elements having non-zero value come after them while maintaining their relative order.

For example :

Consider the array { 1, 1, 0, 2, 0 }. 
For the given array the modified array should be {0,0,1,1,2} . 
Arrays { 0, 0, 1, 2, 1 } and  { 0, 0, 2, 1, 1 } are not the correctly reorganized array even if they have all the zero values pushed to the left as in both the arrays the relative order of non-zero elements is not maintained.

Follow Up :

Can you solve the problem in linear time, and constant space?

You are given an array of integers and a number ‘K’. You can pair two elements in the array 'ARR' if the absolute difference between them is strictly less than ‘K’. Your task is to find the maximum possible sum of disjoint pairs among all the pairs of numbers you can obtain.

The sum of a pair is the sum of the elements in the pair.

For Example:

Input: ARR[] = {3, 5, 10, 15, 17, 12, 9}, K = 4
Output: 62

Then disjoint pairs with the absolute difference less than K are 
(3, 5), (10, 12), (15, 17)  
So maximum sum which we can get is 3 + 5 + 12 + 10 + 15 + 17 = 62

Note:

Note that an alternate way to form disjoint pairs is, (3, 5), (9, 12), (15, 17), but this pairing produces a lesser sum.

There are 25 horses among which you need to find out the fastest 3 horses. You can conduct race among at most 5 to find out their relative speed. At no point, you can find out the actual speed of the horse in a race. Find out how many races are required to get the top 3 horses. (GFG Link:https://www.geeksforgeeks.org/puzzle-9-find-the-fastest-3-horses/)

You are given two arrays of coefficients and degrees of a polynomial expression. You need to simplify the polynomial in general form by evaluating and simplifying the expression.

For Example:

If the given polynomial equation is “5x ^ 3 + 2x ^ 3 + 6x ^ 4 + 2”. There are two terms of exponent or degree 3 and they are 5x ^ 3 and 2x ^ 3. Both these terms will get added and form 7x ^ 3, so the given polynomial will be simplified as 7x ^ 3 + 6x ^ 4 + 2. Now by arranging the expression in the decreasing order of the degrees, we will have 6x ^ 4 + 7x ^ 3 + 2 and hence the result.