可能重复： 使用按位运算符查找是否将每个偶数位设置为0
另一个例子没有真正回答我的问题，所以这里是情况：
如果位序列中的所有均值都设置为0，则需要返回1，否则返回0。 - 我不能使用条件语句！
所以我有一个数字0x7f（01111111）
我可以通过面具0xAA（10101010）
这给了我：00101010
我只需要做一个0或1所以我!!（00101010），这将给我一个布尔值，但它返回1但我需要一个0所以我可以否定它或使用不同的掩码。
我一直跟着这个并且它让我疯狂，请帮助并记住这些运算符没有条件语句：
！ 〜＆^ | + << >>
Possible Duplicate: Find if every even bit is set to 0 using bitwise operators
The other example didnt really answer my question so here is the situation:
I need to return 1 if all evens in the bit sequence are set to 0 and return 0 otherwise. -I cant use conditional statements!
So I have a number 0x7f (01111111)
I can and by a mask of 0xAA(10101010)
that gives me: 00101010
I need to do only a 0 or 1 so I !!(00101010) and that will give me the boolean value for it but it returns a 1 but I need a 0 so I can negate it or use a different mask.
I keep going in circles with this and its driving me nuts please help and remember no conditional statements just these operators:
! ~ & ^ | + << >>
最满意答案
我错过了什么吗？ 结果你得到00101010 ，所以不是所有的平均值都是0.在这种情况下你应该返回0，但是你!! （ 两次否定）结果。 为什么？ 非零值被否定为假，然后被否定为真，这是1 ...正好与你需要的相反...
其他方式：使用0x15（00010101），所有均匀为0，ANDAD与0xAA给出0，否定给出true，再次否定给出false，结果为0 ...
Am I missing something? You get 00101010 as a result, so not all evens are 0. in that case you should return 0, but you !! (twice negate) the result. Why that? The non-zero value is negated to false, which is then negated to true, which is 1... Just the opposite of what you need...
Other way round: with 0x15 (00010101), all evens are 0, ANDing with 0xAA gives 0, negated gives true, again negated gives false, result is 0...
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