Set all the bits in given range of a number
Given a non-negative number n and two values l and r. The problem is to set the bits in the range l to r in the binary representation of n, i.e, to unset bits from the rightmost lth bit to the rightmost r-th bit.
Constraint: 1 <= l <= r <= number of bits in the binary representation of n.
Input : n = 17, l = 2, r = 3 Output : 23 (17)10 = (10001)2 (23)10 = (10111)2 The bits in the range 2 to 3 in the binary representation of 17 are set. Input : n = 50, l = 2, r = 5 Output : 62
Approach: Following are the steps:
1. Find a number 'range' that has all set bits in given range. And all other bits of this number are 0. range = (((1 << (l - 1)) - 1) ^ ((1 << (r)) - 1)); 2. Now, perform "n = n | range". This will set the bits in the range from l to r in n.
Time Complexity : O(1)
Auxiliary Space : O(1)
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