Weird sum value for CS50 pset1- Greedy challenge - c

Question

I have finished my code for Greedy challenge in PSET1's CS50
However, the total count of coins returns is quite large. When I look further into it, it seems that my nickels coins count is huge (4381344 coins for 0.48 cent).
Call me stupid but I have been pulling my hair for a while because of this. Anyone can point out why?
#include <cs50.h>
#include <stdio.h>
#include <math.h>
// You want to:
// get user input of a float
// check float
// Loop: minus money with biggest coins unit until negative
// then loop and loop
// until 1
// then count the number of loop (by assign a variable to count)
int main(void)
{
float money_give;
int quarters= 25, qc, dimes = 10, dc, nickels= 5, nc,pennies= 1, pc;
do
{
printf("O hai! How much change is owed?\n");
money_give = get_float();
}
while (money_give <= 0.0);
money_give = money_give * 100;
int money = (int)round(money_give);
while (money >= quarters)
{
qc = money / quarters;
money = money % quarters;
}
while (money >= dimes)
{
dc = money / dimes;
money = money % dimes;
}
while (money >= nickels)
{
nc = money / nickels;
money = money % nickels;
}
while (money >= pennies)
{
pc = money / pennies;
money = money % pennies;
}
printf("%i\n",pc+ nc+ qc +dc);
printf("%i\n",nc);
printf("%i\n",qc);
printf("%i\n",dc);
printf("%i\n",pc);
}
Oh and the output is:
O hai! How much change is owed?
0.48
4381350
4381344
1
2
3

Answer 1

You forgot to initialize your variables. Change:
int quarters= 25, qc, dimes = 10, dc, nickels= 5, nc,pennies= 1, pc;
into:
int quarters= 25, qc = 0, dimes = 10, dc = 0, nickels= 5, nc = 0, pennies= 1, pc = 0;
What happened was that because nc had not been initialized, then it started with being equal to whatever garbage was already there in the memory where it was being stored.
Then when you came to this part, it did not get a new value because money was less than nickels:
while (money >= nickels)
{
nc = money / nickels;
money = money % nickels;
}
Therefore it never got assigned a new value instead of the garbage it started with.
The lesson from this: Always initialize your variables.