Software Engineer

You are given an array ‘NUMS’ of length ‘N’. You are also given an integer ‘TARGET’.

Return an array of all the unique quadruplets [ ‘NUMS[ a ]’, ‘NUMS[ b ]’, ‘NUMS[ c ]’, ‘NUMS[ d ]’ ] with the following conditions:

i. 0 <= a, b, c, d < ‘N’ and a, b, c, and d are distinct.

ii. NUMS[ a ] + NUMS[ b ] + NUMS[ c ] +NUMS[ d ] = TARGET

Return the array in any order.

Note:

(NUMS[ a ], NUMS[ b ], NUMS[ c ], NUMS[ d ]), (NUMS[ a ], NUMS[ d ], NUMS[ c ], NUMS[ b ]), (NUMS[ a ], NUMS[ c ], NUMS[ b ], NUMS[ d ])... all of them are treated or considered the same quadruplets.

Two quadruplets are different if there is any integer in one quadruplet which is not in the other.

The solution will be verified by the number of valid quadruplets returned. In the output, only the number of valid quadruplets will be printed.

Example:

Input: ‘N’ = 5,  ‘TARGET’ = 5, ‘NUMS’ = [ 1, 2, 1, 0, 1 ]

Output: 1.

There is only one unique quadruplet with sum = 5 and that is [1, 2, 1, 1].

You are given a string s, which may contain words, extra spaces between words, and leading or trailing spaces.

Your task is to reformat the string to a "normalized" version. A normalized string has all its words separated by exactly one space, with no spaces at the beginning or end of the string.

They asked me to design the LinkedIn connection feature.

She asked me about my views on AI.