Exactly, just truncate the iteration to the first k elements. Need a hash table to get the modified values, so it breaks the "O(1) extra space" condition, but t

Exactly, just truncate the iteration to the first k elements. Need a hash table to get the modified values, so it breaks the "O(1) extra space" condition, but that condition is bullshit anyway, you're already using O(k) space to store the numbers you find, an extra hash table is also O(k) space. http://ideone.com/5uwqNO http://ideone.com/5uwqNO