A number is called faithful if you can write it as the sum of distinct powers of 7. e.g., 2457 = 7 + 72 + 74 . If we order all the faithful numbers, we get the sequence 1 = 70, 7 = 71, 8 = 70 + 71, 49 = 72, 50 = 70 + 72 . . . and so on. Given some value of N, you have to find the N'th faithful number.
N = 3Output:8Explanation:8 is the 3rd Faithful number.
N = 7Output:57Explanation:57 is the 7th Faithful number.
You don't need to read input or print anything. Your task is to complete the function nthFaithfulNum() which takes an Integer N as input and returns the answer.
Expected Time Complexity: O(log(N)) Expected Auxiliary Space: O(log(N))