Program to calculate Percentile of a student based on rank

Given the rank of a student and the total number of students appearing in an examination, the task is to find the percentile of the student. 
 

The percentile of a student is the % of the number of students having marks less than him/her.

Examples: 
 

Input: Rank: 805, Total Number of Students Appeared: 97481 
Output: 99.17 
Explanation: 
((97481 - 805) / 97481) * 100 = 99.17
Input: Rank: 65, Total Number of Students Appeared: 100 
Output: 35 
Explanation: 
((100 - 65) / 100) * 100 = 35 
 

Approach 
The formula to calculate the percentile when the rank of the student and the total number of students appeared is given is:
 

((Total Students - Rank) / Total Students) * 100

Below is the implementation of the above formula: 
 

C++ 

99.1742

Performance Analysis: 
 

• Time Complexity: In the above approach, we are able to calculate percentile using a formula in constant time, so the time complexity is O(1). 
   
• Auxiliary Space Complexity: In the above approach, we are not using any extra space apart from a few constant size variables, so Auxiliary space complexity is O(1).