Program not assigning proper values to variables - c

Question

I am new to programming in general, recently decided to get serious about try to learn C. I am trying to build a light account program using nested loops and arrays.
I'm trying to build the program in CodeBlocks. My program is a little rough,
1) my first issue is that after my program asks how many weeks of work has been done, it then has grabs a value for the next loop, ignoring the value of weeks for at least the first loop.
2) Entering any integer other than "1" causes tax to pull a random value from memory, and even worse, it can overwrite the value for "weeks" despite there not being another scanf function for "weeks", often leading to the for...loop depending on the variable weeks to loop well into the millions.
3) I haven't programmed pathways 5 & 6 for void menu() yet due to the rest of the program not functioning properly
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
int pay = 10;
const int overtime;
float taxrate;
int hours; //user input for hours worked
int gross; //calculated integer for gross pay
int tax; //calculated integer for taxes
int net; //calculated integer for net pay
int gross_total = 0; //non printed value for summing gross
int i; //condition to exit loop
void tax_rate();
void menu();
void cust_paid_yn();
void hours_worked();
int menu_input;
int menu_break;
char c;
int unpaid;
int weeks;
int j;
int week_numb_array[];
int gross_array[];
int tax_array[];
int gross_total_array[];
void printfinal();
int main(void)
{
menu();
printf("How many weeks have been worked?\n");
scanf("%d\n", &weeks);
for (int j = 0; j <= weeks; j++)
{
while (menu_input = 1 || 2 || 3 || 4)
{
hours_worked();
while ( hours != 1)
{
//uses hours to calculate gross, taxes, and net
gross = (hours * pay);
//use loop and gross to determine tax
tax_rate();
//uses hours to calculate taxes, net, and gross_total
tax = (gross * taxrate);
net = (gross - tax);
gross_total += (net);
gross_array[j] = gross;
tax_array[j] = tax;
gross_total_array[j] = gross_total;
break;
}
printf("\nexited out of menu_input loop\n");
break;
}
printf("\nexited out of tax loop\n");
printf("\n \n %d\n \n", weeks);
printf("\n \n %d\n \n", j);
}
printf("\nexited out of for...loop\n");
j = 0;
printfinal();
return 0;
}
void printfinal()
{
for (j = 0; j <= weeks; j++)
{
//Prints the title headers: gross pay, taxes and net pay
printf("Week Numb\t gross pay \t taxes \t net pay\n");
//Prints the calculations for gross, taxes, and net
printf("week 1\t\t %ld \t\t %ld \t\t %ld \t\n", gross_array[j],
tax_array[j], gross_total_array[j]);
}
return 0;
}
void tax_rate()
{
//use loop and gross to determine tax
if (gross <= 300)
{
taxrate = .15;
}
else if (gross <= 450)
{
taxrate = .20;
}
else if (gross >= 451)
{
taxrate = .25;
}
return 0;
}
void menu()
{
printf("Please make a selection from the following options\n 1) Set Pay
Rate to 8.75\n 2) Set Pay Rate to 9.33\n 3) Set Pay Rate to 10.00\n 4) Set Pay Rate to 11.20\n 5) Print Out List\n 6) Quit\n");
scanf("%d", &menu_input);
switch (menu_input)
{
case 1:
printf("Pay Rate set to 8.75\n");
menu_break = 0;
pay = 8.75;
break;
case 2:
printf("Pay Rate set to 9.33\n");
menu_break = 0;
pay = 9.33;
break;
case 3:
printf("Pay Rate set to 10.00\n");
menu_break = 0;
pay = 10.00;
break;
case 4:
printf("Pay Rate set to 11.20\n");
menu_break = 0;
pay = 11.20;
break;
case 5:
menu_break = 1;
printf("List Printed\n");
break;
case 6:
printf("QUIT\n");
menu_break = 2;
break;
default:
printf("Unknown\n");
menu_break = 3;
break;
}
return 0;
}
void cust_paid_yn()
{
for (i=0; i<1; 1)
{
//get input for whether cust. was paid
printf("Was customer paid this week? (y/n)\n");
scanf("%c", &c);
//loop to check for y/n response
switch (c)
{
case 'y':
printf("\n");
i=1;
hours = (hours + unpaid);
unpaid = 0;
break;
case 'n':
printf("hours logged\n");
i=1;
unpaid = (unpaid + hours);
hours = 0;
break;
default:
printf("\n");
i=0;
break;
}
break;
}
return 0;
}
void hours_worked()
{
//asks how many hours were worked
printf("How many hours were worked?\n \nIf no work was done enter 0\n");
//gets user input for hours worked
scanf("%ld", &hours);
return 0;
}
I just want to create a program that:
1) gets user input for how many time the program will loop (see weeks var)
2) print out user data using an array
Any help and suggestions are greatly appreciated, I'm at my wits end on why my program pulls random values from memory.