CT & Discrete-Time Systems Series RC Circuit

I have a question as shown in the figure above. I wrote the code below but I know it's not correct. How do I fix this problem.

clc;
clear all;
close all;

syms R C y t

input = 'heaviside(t) - heaviside(t-1)'
y = dsolve(['Dy + 1/R/C*y = 1/R/C*',char(input)], 'y(0) = 0');
g = subs(y,[R C], [1e5 1e-6]);
h = ezplot(g,[-2 6]);
set(h,'linewidth',3)
axis([-2 6 -0.5 1.2])
grid 

function y = heaviside(x)
y = zeros(size(x));
y(x > 0) = 1;
y(x == 0) = NaN;
end

Thank you for your help.