Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>I saw this question in Cracking the Coding interview book.</p> <p>Let’s try to solve this by “re-wording” the problem We will re-word the problem until we get something that has removed all if statements</p> <p>Rewording 1: If a > b, return a; else, return b<br> Rewording 2: If (a - b) is negative, return b; else, return a<br> Rewording 3: If (a - b) is negative, let k = 1; else, let k = 0 Return a - k * (a - b) <br> Rewording 4: Let c = a - b Let k = the most significant bit of c Return a - k * c</p> <pre><code>int getMax(int a, int b) { int c = a - b; int k = (c &gt;&gt; ((sizeof(int) * CHAR_BIT) - 1)) &amp; 0x1; int max = a - k * c; return max; } </code></pre> <p>Source: <a href="http://rads.stackoverflow.com/amzn/click/098478280X" rel="nofollow">http://www.amazon.com/Cracking-Coding-Interview-Programming-Questions/dp/098478280X</a></p> <p>Edit: This code works even when a-b overflows. Let k equal the sign of a-b such that if a-b >=0, then k is 1, else k=0.Let q be the inverse of k. Above code overflows when a is positive or b is negative, or the other way around. If a and b have different signs, then we want the k to equal sign(a). </p> <pre><code>/* Flips 1 to 0 and vice-versa */ public static int flip(int bit){ return 1^bit; } /* returns 1 if a is positive, and 0 if a is negative */ public static int sign(int a){ return flip((a &gt;&gt; ((sizeof(int) * CHAR_BIT) - 1)) &amp; 0x1); } public static int getMax(int a, int b){ int c = a - b; int sa = sign(a-b); // if a&gt;=0, then 1 else 0 int sb = sign(a-b); // if b&gt;=1, then 1 else 0 int sc = sign(c); // depends on whether or not a-b overflows /* If a and b have different signs, then k = sign(a) */ int use_sign_of_a = sa ^ sb; /* If a and b have the same sign, then k = sign(a - b) */ int use_sign_of_c = flip(sa ^ sb); int k = use_sign_of_a * sa + use_sign_of_c * sc; int q = flip(k); //opposite of k return a * k + b * q; } </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POFinding MAX of numbers without conditional IF statements c++
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USmanny
    1. USmanny
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. CONice for usage with smaller numbers, but this is broken for some edge cases - where `a - b` would be `< std::numeric_limits<int>::min()`.
      singulars
      1. PO
      1. USTony Delroy
    2. COYou're assuming an integer contains 32 bits. Why not use `(sizeof(int) * CHAR_BIT) - 1`?
      singulars
      1. PO
      1. US0x499602D2
    3. COyes, you are right. Thanks for pointing it out!
      singulars
      1. PO
      1. USmanny
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload