Given a string S of lowercase alphabets, check if it is isogram or not. An Isogram is a string in which no letter occurs more than once.
Example 1:
Input:
S = machine
Output: 1
Explanation: machine is an isogram
as no letter has appeared twice. Hence
we print 1.
Example 2:
Input:
S = geeks
Output: 0
Explanation: geeks is not an isogram
as 'e' appears twice. Hence we print 0.
Your Task:
This is a function problem. You only need to complete the function isIsogram() that takes a string as a parameter and returns either true or false.
Expected Time Complexity: O(N).
Expected Auxiliary Space: O(Number of distinct characters).
Note: N = |S|
Constraints:
1 <= |s| <= 10^{3}

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