How would I use a while loop to get a certain amount of inputs from a described interval?

The problem asks for inputs for 3 constants (a,b,c) and an x value to output y depending on the value of x.

bascially there's 3 cases and this is the code I have so far.

a=input('Please enter value a: ');

b=input('Please enter value b: ');

c=input('Please enter value c: ');

x=input('Enter argument for x: ');

if x<-1    %case 1
    
    y=a*exp(x^3)-b*x^2+x-c     
    
elseif -1<=x<5     %case 2
    
   y=2*log(x)-(a*x-1)^3+c^2
   
elseif x>=5      %case 3
    
    y=a*exp(-x^2)/log(x)+b/x^2-c 
    
end

This is part of the problem description which I'm having trouble with and would appreciate any help:

Your program should use a while loop to evaluate y for scanned x in each of the above three cases. If you input x from the same interval more than twice, your program should ask you to input x from another interval, until you input x twice from each interval.

Answer 1

[KSSV]

c1 = 0 ;
c2 = 0 ;
c3 = 0 ;
while true
    a=input('Please enter value a: ');
    b=input('Please enter value b: ');
    c=input('Please enter value c: ');
    x=input('Enter argument for x: ');
    
    if x<-1    %case 1
        c1 = c1+1 ;        
        y=a*exp(x^3)-b*x^2+x-c
        if c1 > 2
            c1 = 0 ;
            fprintf('Please input x from other intervel: you entered x<-1, twice\n')
        end
    elseif -1<=x<5     %case 2
        c2 = c2+1 ;
        y=2*log(x)-(a*x-1)^3+c^2
         if c2 > 2
             c2 = 0 ;
            fprintf('Please input x from other intervel: you entered -1<x<5, twice\n')
        end
        
    elseif x>=5      %case 3
        c3 = c3+1 ;
        y=a*exp(-x^2)/log(x)+b/x^2-c
         if c3 > 2
             c3 = 0 ;
            fprintf('Please input x from other intervel: you entered x>=5, twice\n')
        end
    end
end