Sorting algorithm in Javascript

Question

Write a JavaScript callback for the jQuery function $(\"#sort\").click. Allow the user to enter three numbers in any order. Output the numbers in ord

Answer 1

Some great jQuery answers here, I'll cover the comparisons part.

You don't need five comparisons, just three (or two if you're lucky). Compare a and b, and swap them if a > b. Then compare c and b. If c > b, you're done, otherwise compare c and a:

if (a > b)
  x = a, a = b, b = x;

if (c < b)
  if (c < a)
    result = [c, a, b];
  else
    result = [a, c, b];
else
  result = [a, b, c];

If all numbers are 32-bit positive ints, you can sort them without any comparisons at all:

min = function(a,b) { return b + ((a-b) & ((a-b)>>31)) }
max = function(a,b) { return a - ((a-b) & ((a-b)>>31)) }

x = min(a, min(b, c));
z = max(a, max(b, c));
y = (a + b + c) - (x + z);

result = [x, y, z];