SDE - 1

Given a string "pattern", which contains only two types of characters ‘(’, ‘)’.

Your task is to find the minimum number of parentheses either ‘(’, ‘)’ we must add the parentheses in string ‘pattern’ and the resulted string is valid.

Condition for valid string-

Every opening parenthesis ‘(’ must have a correct closing parenthesis ‘)’.

Example - ‘(()(()))’, ‘()()()’, ‘((()))’ are valid string, and ‘(((’, ‘(()’, ‘)(())’ are invalid string.

Note:

1. You are not required to print the output explicitly, it has already been taken care of. Just implement the function and return the minimum number of parentheses required to make a string valid.

You have been given a 9x9 2d integer matrix 'MAT' representing a Sudoku puzzle. The empty cells of the Sudoku are filled with zeros, and the rest of the cells are filled with integers from 1 to 9. Your task is to fill all the empty cells such that the final matrix represents a Sudoku solution.

Note:

A Sudoku solution must satisfy all the following conditions-
1. Each of the digits 1-9 must occur exactly once in each row.
2. Each of the digits 1-9 must occur exactly once in each column.
3. Each of the digits 1-9 must occur exactly once in each of the 9, 3x3 sub-grids of the grid.

You can also assume that there will be only one sudoku solution for the given matrix.

You have been given a singly Linked List of 'N' nodes with integer data and an integer 'K'.

Your task is to remove the 'K'th node from the end of the given Linked List and return the head of the modified linked list.

Example:

Input : 1 -> 2 -> 3 -> 4 -> 'NULL'  and  'K' = 2
Output: 1 -> 2 -> 4 -> 'NULL'
Explanation:
After removing the second node from the end, the linked list become 1 -> 2 -> 4 -> 'NULL'.