SDE - 1

You are given a positive integer 'N'. Your task is to return all the prime numbers less than or equal to the 'N'.

Note:

1) A prime number is a number that has only two factors: 1 and the number itself.

2) 1 is not a prime number.

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”.

You are given a 'M' x 'N' matrix of characters, 'CHARACTER_MATRIX' and a string 'WORD'. Your task is to find and print all occurrences of the string in the given character matrix. You are allowed to search the string in all eight possible directions, i.e. North, South, East, West, North-East, North-West, South-East, South-West.

Note: There should not be any cycle in the output path. The entire string must lie inside the matrix boundary. You should not jump across boundaries, i.e. from row 'N' - 1 to 0 or column 'N' - 1 to 0 or vice versa.

Example:

Consider below matrix of characters,
[ 'D', 'E', 'X', 'X', 'X' ]
[ 'X', 'O', 'E', 'X', 'E' ] 
[ 'D', 'D', 'C', 'O', 'D' ]
[ 'E', 'X', 'E', 'D', 'X' ]
[ 'C', 'X', 'X', 'E', 'X' ]

If the given string is "CODE", below are all its occurrences in the matrix:

'C'(2, 2) 'O'(1, 1) 'D'(0, 0) 'E'(0, 1)
'C'(2, 2) 'O'(1, 1) 'D'(2, 0) 'E'(3, 0)
'C'(2, 2) 'O'(1, 1) 'D'(2, 1) 'E'(1, 2)
'C'(2, 2) 'O'(1, 1) 'D'(2, 1) 'E'(3, 0)
'C'(2, 2) 'O'(1, 1) 'D'(2, 1) 'E'(3, 2)
'C'(2, 2) 'O'(2, 3) 'D'(2, 4) 'E'(1, 4)
'C'(2, 2) 'O'(2, 3) 'D'(3, 3) 'E'(3, 2)
'C'(2, 2) 'O'(2, 3) 'D'(3, 3) 'E'(4, 3)