Ошибка Run-Time Check Failure #3 - The variable 'y' is being used without being initialized

#include "stdafx.h"
#include <iostream>
#include <conio.h>
 
using namespace std;
 
int main()
{
    float q, r, y;
    const int x = 20;
    char e;
    cout << "enter A, B or C" << endl;
    cin >> e;
    switch (e)
    {
    case 1:e = 'A'; y = 100 * fabs((3 * (x*x*x + 5) + exp(2 * x)) / (4.5*(x*x - 9.5)) + (1 / tan(3 * x) + 50));
        q = y*0.1; r = y - q; break;
    case 2:e = 'B'; y = 150 * fabs((8.5*exp(-2 * x) + (5 * (x + 4) + log(fabs(x - 0.2)))) / ((x - 2)*(x - 0.6)) + 100);
        q = y*0.15; r = y - q; break;
    case 3:e = 'C'; ; y = 200 * fabs((4 * x*x*x + 2 * x - cos(3 * x)) / (2 * (3.5*x - 8)) + log(2 * x) + 135);
        q = y*0.2; r = y - q; break;
    default: break;
    }
    cout << "\n y=" << y << " Suma" << endl;
    cout << "\n q=" << q << " Vidrahuvannya" << endl;
    cout << "\n r=" << r << " Suma do vidachi" << endl;
    system("pause");
    return 0;
 
 
 
 
}