## When should you use merge sort?

**Merge Sort** is useful for **sorting** linked lists. **Merge Sort** is a stable **sort** which means that the same element in an array maintain their original positions with respect **to** each other. Overall time complexity of **Merge sort** is O(nLogn). It is more efficient as it is in worst case also the runtime is O(nlogn)

## Is merge sort faster than selection sort?

For example, the **merge**–**sort** algorithm copies elements back and forth to a temporary array during each **merge**. For each comparison, it does several times the work. We’d expect a **merge sort** to be about 40 times **faster than** a **selection sort**. (The actual figure, as it turns out, is around 50 times **faster**.)

## What is the best case running time of merge sort?

Sorting algorithms

Algorithm | Data structure | Time complexity:Best |
---|---|---|

Quick sort |
Array | O(n log(n)) |

Merge sort |
Array | O(n log(n)) |

Heap sort |
Array | O(n log(n)) |

Smooth sort |
Array | O(n) |

## Why is merge sort faster?

Indeed, it is because **merge sort** is implemented recursively that makes it **faster** than the other algorithms we’ve looked at thus far. In part 2 of this series, we’ll look at the runtime complexity of **merge sort**, how this recursion actually makes it more efficient, and how **merge sort** stacks up against other algorithms.

## Which sorting algorithm is fastest?

The time **complexity** of **Quicksort** is O(n log n) in the best **case**, O(n log n) in the average **case**, and O(n^2) in the worst **case**. But because it has the best performance in the average **case** for most inputs, **Quicksort** is generally considered the “fastest” sorting algorithm.

## What’s the best sorting algorithm?

**Quicksort**. **Quicksort** is one of the most efficient sorting algorithms, and this makes of it one of the most used as well. The first thing to do is to select a pivot number, this number will separate the data, on its left are the numbers smaller than it and the greater numbers on the right.

## What is the disadvantage of selection sort?

The primary **disadvantage** of the **selection sort** is its poor efficiency when dealing with a huge list of items. Similar to the bubble **sort**, the **selection sort** requires n-squared number of steps for **sorting** n elements.

## Why is insertion sort better?

**Insertion sort** has a fast best-case running time and is a **good sorting** algorithm to use if the input list is already mostly **sorted**. For larger or more unordered lists, an algorithm with a faster worst and average-case running time, such as mergesort, would be a **better** choice.

## Which sorting algorithm is best for sorted array?

When the array is almost sorted, **insertion sort** can be preferred. When order of input is not known, **merge sort** is preferred as it has worst case time **complexity** of nlogn and it is stable as well. When the array is sorted, insertion and bubble sort gives **complexity** of n but quick sort gives **complexity** of n^2.

## Which is the slowest sorting procedure?

Discussion Forum

Que. | Out of the following, the slowest sorting procedure is |
---|---|

b. | Heap Sort |

c. | Shell Sort |

d. | Bubble Sort |

Answer:Bubble Sort |

## Is Big O average or worst case?

In short, there is no kind of relationship of the type “**big O** is used for **worst case**, Theta for **average case**”. All types of notation can be (and sometimes are) used when talking about best, **average, or worst case** of an algorithm.

## Is Quicksort faster than bubble sort?

Also, for small data set, **bubble sort** or other simple **sorting** algorithm usually works **faster than** more complex algorithms. For example, say **bubble sort** takes 3ms per iteration while **quicksort** takes 20ms. So for an array with 10 items. In this case **bubble sort** takes 10*10*3 = 300ms.

## Is Merge Sort difficult?

The **merge sort** algorithm is a divide and conquer **sorting** algorithm that has a time complexity of O (n log n). Therefore, it is an extremely versatile and reliable **sorting** algorithm. Surprisingly enough, it is also not that **difficult** to implement and understand.

## What is a stable sorting algorithm?

**Stable sorting algorithms** maintain the relative order of records with equal keys (i.e. values). That is, a **sorting algorithm** is **stable** if whenever there are two records R and S with the same key and with R appearing before S in the original list, R will appear before S in the **sorted** list.