# Algorithms | Analysis of Algorithms | Question 9

In a competition, four different functions are observed. All the functions use a single for loop and within the for loop, same set of statements are executed. Consider the following for loops:

`A) ` `for` `(i = 0; i < n; i++)` ` ` `B) ` `for` `(i = 0; i < n; i += 2)` ` ` `C) ` `for` `(i = 1; i < n; i *= 2)` ` ` `D) ` `for` `(i = n; i > -1; i /= 2)` |

If **n** is the size of input(positive), which function is most efficient(if the task to be performed is not an issue)?**(A)** A**(B)** B**(C)** C**(D)** D**Answer:** **(C)****Explanation:** The time complexity of first for loop is O(n).

The time complexity of second for loop is O(n/2), equivalent to O(n) in asymptotic analysis.

The time complexity of third for loop is O(logn).

The fourth for loop doesn’t terminate.

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