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Showing posts with the label bit-manipulation

Power of Two

  I n this post will be discussing how to calculate if a number is a power of two or not. As an example, 8 is a power of two but the number 10 is not. There are many ways we can solve this. First , we will take an approach which is simple and iterative. In this case, we will calculate the power of two one by one and check with the supplied number. The below code illustrates it. bool isPowerofTwo(unsigned num) { auto y = 1; while (0 != y) { if (num == y) return true; if (num < y) return false; y <<= 1; } return false; } Second , assuming, the number is a 32-bit number, this is also an iterative solution. In this scenario, iterating all bits and counting the set bits. Any number which is a power of 2 will have only one bit set and the rest will be zeros. As an example, 8 in binary representation is 1000. Using this observation, we can implement an iterative solution. bool isPowerofTwo(unsigned num) { auto one_count = 0; for (auto index = 0; index < 32;