switchcase.cpp

/*Problem statement
Programming languages have some conditional / decision-making statements that execute when some specific condition is fulfilled.
Switch-case is one of the ways to implement them.
In a menu-driven program, the user is given a set of choices of things to do (the menu) and then is asked to select a menu item.
There are 2 choices in the menu:
Choice 1 is to find the area of a circle having radius 'r'.
Choice 2 is to find the area of a rectangle having dimensions 'l' and 'b'.
You are given the choice 'ch' and an array 'a'.
If ‘ch’ is 1, ‘a’ contains a single number ‘r’. If ‘ch’ is 2, ‘a’ contains 2 numbers, ‘l’ and ‘b’.
Consider the choice and print the appropriate area.
Example :
Input: ‘ch’ = 2 and ‘a’ = [3, 2]
Output: area = 6
Explanation: Since the choice ‘ch’ is 2, we have to print the area of the rectangle having ‘l’ = 3 and ‘b’ = 2, which is 6.
Detailed explanation ( Input/output format, Notes, Images )
Sample Input 1:
2
3 2
Sample Output 1:
6.00000
Explanation of sample input 1 :
Since the choice ‘ch’ is 2, we have to print the area of the rectangle having ‘l’ = 3 and ‘b’ = 2, which is 6.
Sample Input 2:
1
3
Sample Output 2:
28.27433
Explanation of sample input 2 :
Since the choice ‘ch’ is 1, we have to print the area of the circle having ‘r’ = 3, which is approximately 28.274333882308138. Rounded off to 5 decimal places, we get 28.27433.
Expected time complexity :
The expected time complexity is O(1).
Constraints :
1 <= ‘ch’ <= 2
1 <= ‘r’ <= 100
1 <= ‘l’, ‘b’ <= 100

Time limit: 1 second
*/

#include <iostream>
#include <vector>
#include <cmath>
using namespace std;

double areaSwitchCase(int ch, vector<double> a) {
    switch (ch) {
        case 1: {
            double r = a[0];
            return M_PI * r * r;
        }
        case 2: {
            double l = a[0];
            double b = a[1];
            return l * b;
        }
        
    }
}

int main() {
    
    int ch1 = 2;
    vector<double> a1 = {3, 2};
    cout << "Area: " << areaSwitchCase(ch1, a1) << endl;  

    
    int ch2 = 1;
    vector<double> a2 = {3};
    cout << "Area: " << areaSwitchCase(ch2, a2) << endl;  

    return 0;
}