SDE - 2

You are given a string 'S' of length 'N', you need to find the frequency of each of the characters from ‘a’ to ‘z’ in the given string.

Example :

Given 'S' : abcdg
Then output will be : 1 1 1 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

You are given an array 'ARR' of integers of length N. Your task is to find the first missing positive integer in linear time and constant space. In other words, find the lowest positive integer that does not exist in the array. The array can have negative numbers as well.

For example, the input [3, 4, -1, 1] should give output 2 because it is the smallest positive number that is missing in the input array.

You are given an array Arr consisting of N integers. Your task is to find all the unique permutations of the given array. For e.g if the array is {1, 1, 2}, the unique permutations of this array are {1, 1, 2}, {1, 2, 1}, {2, 1, 1}. Note that the total number of permutations of {1,1,2} is equal to 6 but out of those {1,1,2} and {1,2,1} occur twice.

Note:

1. There might be duplicates present in the array.
2. The order of the permutations in the output does not matter.
3. Do not use any kind of in-built library functions to find the answer.

You are given an array/list ‘ARR’ consisting of ‘N’ non - negative integers and an integer ‘K’. Your task is to return the K-th smallest element of the array.

For example :-

Given an array/list ‘ARR' = [ 3, 2, 4, 5, 6 ] and 'K' = 3. The 3rd smallest element is "4" because the order of numbers is [ 2, 3, 4, 5, 6 ].

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