SDE - 1

You are given a string ‘STR’ consisting of lowercase English alphabets. Your take is to find out the minimum number of character deletions required such that each character in the final string has a unique frequency.

You are given a N x M matrix of integers, return the spiral path of the matrix

Example Of Spiral Path

Given an unsorted array of integers, you have to move the array elements in a way such that all the zeroes are transferred to the end, and all the non-zero elements are moved to the front. The non-zero elements must be ordered in their order of appearance.

For example, if the input array is: [0, 1, -2, 3, 4, 0, 5, -27, 9, 0], then the output array must be:

[1, -2, 3, 4, 5, -27, 9, 0, 0, 0].

Expected Complexity: Try doing it in O(n) time complexity and O(1) space complexity. Here, ‘n’ is the size of the array.

Design google calendar.

You are given the root node of a binary tree consisting of ‘N’ nodes. Your task is to find the number of good nodes in the given binary tree.

A good node is defined as good if there are no nodes with a value greater than X’s value in the path from the root to X.

You are given a root node ‘ROOT’.Your task is to return the number of good nodes.

Example:

Elements are in the level order form. The input consists of values of nodes separated by a single space in a single line. In case a node is null, we take -1 in its place.

For example, the input for the tree depicted in the below image would be :

1
2 3
4 -1 5 6
-1 7 -1 -1 -1 -1
-1 -1

Explanation :
Level 1 :
The root node of the tree is 1

Level 2 :
Left child of 1 = 2
Right child of 1 = 3

Level 3 :
Left child of 2 = 4
Right child of 2 = null (-1)
Left child of 3 = 5
Right child of 3 = 6

Level 4 :
Left child of 4 = null (-1)
Right child of 4 = 7
Left child of 5 = null (-1)
Right child of 5 = null (-1)
Left child of 6 = null (-1)
Right child of 6 = null (-1)

Level 5 :
Left child of 7 = null (-1)
Right child of 7 = null (-1)

The first not-null node (of the previous level) is treated as the parent of the first two nodes of the current level. 

The second not-null node (of the previous level) is treated as the parent node for the next two nodes of the current level and so on.

The input ends when all nodes at the last level are null (-1).

Note :

The above format was just to provide clarity on how the input is formed for a given tree. 

The sequence will be put together in a single line separated by a single space. Hence, for the above-depicted tree, the input will be given as:

1 2 3 4 -1 5 6 -1 7 -1 -1 -1 -1 -1 -1

You are given a Binary Tree of 'n' nodes.

The Top view of the binary tree is the set of nodes visible when we see the tree from the top.

Find the top view of the given binary tree, from left to right.

Example :

Input: Let the binary tree be:

Output: [10, 4, 2, 1, 3, 6]

Explanation: Consider the vertical lines in the figure. The top view contains the topmost node from each vertical line.

Design a keyword search engine