- Data Structure
- Networking
- RDBMS
- Operating System
- Java
- MS Excel
- iOS
- HTML
- CSS
- Android
- Python
- C Programming
- C++
- C#
- MongoDB
- MySQL
- Javascript
- PHP
- Physics
- Chemistry
- Biology
- Mathematics
- English
- Economics
- Psychology
- Social Studies
- Fashion Studies
- Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Why is it faster to process a sorted array than an unsorted array in C++?
In C++, it is faster to process a sorted array than an unsorted array because of branch prediction. In computer architecture, a branch prediction determines whether a conditional branch (jump) in the instruction flow of a program is likely to be taken or not.
Let’s take an example −
if(arr[i] > 50) { Do some operation B } else { Do some operation A }
If we run this code for 100 elements in unsorted and sorted order below things will be happened −
For sorted array −
1, 2, 3, 4, 5, …… 50, 51………100 A, A, A, A, A A, B B
It will load the correct branch in the pipeline and correct sequence
A, A, A, A, A, A, A, A A, B B
For unsorted array −
5, 51, 6, 90, 4, 49, 60… A, B, A, B, A, A, A, B
Branch prediction doesn’t play a significant role here. It is very difficult to predict the right operation between A and B.
Advertisements