division

问题 Ok so my question: I have a table itemconfig where there is lots of data concerning items stored in our warehouses. I need to select a special group of items so I can do some job related testing. So far I've been doing the math in my head as I scroll through the database but there must be an easier way. Within itemconfig I want to specifically look at columns case_qty and pal_qty and itm_num. What I would like to do is select all itm_num where pal_qty / case_qty is greater than say 500 . This

问题 gcc generates floating code that raises SIGFPE for the following code: #include <limits.h> int x = -1; int main() { return INT_MIN % x; } However I can find no statement in the standard that this code invokes undefined or implementation-defined behavior. As far as I can tell, it's required to return 0. Is this a bug in gcc or am I missing some special exception the standard makes? 回答1: You are probably right that this can be considered as a bug in the actual standard. The current draft

问题 Does anyone know the steps for dividing unsigned binary integers using non-restoring division? It's hard to find any good sources online. i.e if A = 101110 and B = 010111 how do we find A divided by B in non-restoring division? What do the registers look like in each step? Thanks! 回答1: (My answer is a little late-reply. But I hope it will be useful for future visitors) Algorithm for Non-restoring division is given in below image : In this problem, Dividend (A) = 101110, ie 46, and Divisor (B)

问题 Does anyone know the steps for dividing unsigned binary integers using non-restoring division? It's hard to find any good sources online. i.e if A = 101110 and B = 010111 how do we find A divided by B in non-restoring division? What do the registers look like in each step? Thanks! 回答1: (My answer is a little late-reply. But I hope it will be useful for future visitors) Algorithm for Non-restoring division is given in below image : In this problem, Dividend (A) = 101110, ie 46, and Divisor (B)

问题 I'm trying to do a similar thing to what is posted in this question: Python Pandas - n X m DataFrame multiplied by 1 X m Dataframe I have an n x m DataFrame, with all non-zero float values, and a 1 x m column, with all non-zero float values, and I'm trying to divide each column in the n x m dataframe by the values in the column. So I've got: a b c 1 2 3 4 5 6 7 8 9 and x 11 12 13 and I'm looking to return: a b c 1/11 2/11 3/11 4/12 5/12 6/12 7/13 8/13 9/13 I've tried a multiplication

问题 In my Xna game, I am trying to have my playfield scale to the screen that it is running on. To do this, I use proportions to find the percent that the real window is scaled relative to my playfield. To do this, I divide the real width by the virtual width: float _percent = _realViewport.Width / this._viewport.Width; I always get 0, though, in the _percent variable. I set up a debug stop point at that line in my code, and analyzed the variables. this._viewport.Width equals 640, and

问题 print(10**40//2) print(int(10**40/2)) Output of the codes: 5000000000000000000000000000000000000000 5000000000000000151893014213501833445376 Why different values? Why the output of the second print() looks so? 回答1: The floating point representation of 10**40//2 is not accurate: >>> format(float(10**40//2), '.0f') '5000000000000000151893014213501833445376' That's because floating point arithmetic is only ever an approximation, especially when you go beyond what your CPU can accurately model

问题 I tried performing following typecast operation in Python 3.3 int( 10**23 / 10 ) Output: 10000000000000000000000 And after increasing power by one or further int( 10**24 / 10 ) Output: 99999999999999991611392 int( 10**25 / 10 ) Output: 999999999999999983222784 Why is this happening? Although a simple typecasting like int( 10**24 ) Output: 1000000000000000000000000 is not affecting the values. 回答1: You are doing floating-point division with the / operator. 10**24/10 happens to have an inexact

问题 I've got that question on my Computer Architecture Exam on Informatics last semester : "Why 'DIV EDX' in MASM always generates processor exception?" What is the mechanism which generates exception? 回答1: When you do 1-operand division on x86 CPUs, EDX:EAX (64 bit) is divided by the 1st operand (32 bit). The result is stored in EAX (32 bit). So when you divide by EDX:EAX by EDX, what you essentially get is (EDX * 0x100000000 + EAX) / EDX, which result is always above 0x100000000 and does not

问题 http://docs.oracle.com/javase/6/docs/api/java/util/Random.html#nextInt%28int%29 says: The algorithm is slightly tricky. It rejects values that would result in an uneven distribution (due to the fact that 2^31 is not divisible by n). The probability of a value being rejected depends on n. The worst case is n=2^30+1, for which the probability of a reject is 1/2, and the expected number of iterations before the loop terminates is 2. The algorithm: int bits, val; do { bits = next(31); val = bits