DNA’S DSA HACK SERIES - PART 12 скачать в хорошем качестве

DNA’S DSA HACK SERIES - PART 12

This video explains how to solve the "Reverse Bits" problem (0:08) (Question #190 in the DNA's DSA Hack Series). The problem requires reversing the 32 bits of a given integer. Here's a breakdown of the key points: Understanding the Problem (0:46): You're given an integer, and you need to reverse its 32-bit binary representation. For example, if the binary is 011..., it becomes ...110. The "n is Even" Constraint (1:13): This constraint is crucial. If 'n' were odd, its last bit would be '1'. Reversing this would make the first bit '1', potentially changing a positive integer into a negative one because the first bit indicates the sign in a signed integer (1:16-1:45). Solution Approach (1:48): Convert to Binary String (1:52): Convert the given decimal integer into a binary string. The video mentions using built-in functions like to_string in C++ (2:01-2:18). Reverse the String (2:19): Reverse the binary string using a reverse function (e.g., s.begin() to s.end() in C++) (2:21-2:38). Convert back to Decimal (2:39): Convert the reversed binary string back into a decimal integer (2:43-2:46). Code Implementation (C++) (3:04): The video briefly shows the code structure, highlighting two functions: one for decimal-to-binary conversion and another for binary-to-decimal conversion (3:08-3:30). These functions utilize built-in C++ functions from STL files. The core logic involves converting, reversing the string, and then converting back (3:34-3:48).