lc190. Reverse Bits

190. Reverse Bits

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Share Reverse bits of a given 32 bits unsigned integer.

Example 1:

Input: 00000010100101000001111010011100 Output: 00111001011110000010100101000000 Explanation: The input binary string 00000010100101000001111010011100 represents the unsigned integer 43261596, so return 964176192 which its binary representation is 00111001011110000010100101000000. Example 2:

Input: 11111111111111111111111111111101 Output: 10111111111111111111111111111111 Explanation: The input binary string 11111111111111111111111111111101 represents the unsigned integer 4294967293, so return 3221225471 which its binary representation is 10101111110010110010011101101001.

Note:

Note that in some languages such as Java, there is no unsigned integer type. In this case, both input and output will be given as signed integer type and should not affect your implementation, as the internal binary representation of the integer is the same whether it is signed or unsigned. In Java, the compiler represents the signed integers using 2's complement notation. Therefore, in Example 2 above the input represents the signed integer -3 and the output represents the signed integer -1073741825.

思路：转成字符串，翻转，int(s,2)输出

class Solution:
    # @param n, an integer
    # @return an integer
    def reverseBits(self, n):
        s = bin(n)[2:]
        s = s.zfill(32)[::-1]
        return int(s,2)
复制代码

tips:

Python zfill()方法 Python 字符串 Python 字符串 描述 Python zfill() 方法返回指定长度的字符串，原字符串右对齐，前面填充0。

语法 zfill()方法语法：

str.zfill(width) 参数 width -- 指定字符串的长度。原字符串右对齐，前面填充0。

转载于:https://juejin.im/post/5ce4b5836fb9a07ef16158db