pointer problems

the code hasn't really changed from the one above. right now i am playing around with pointers trying to get the balance to stay changed when i add to it or subtract from it

Code:

---

int main(){
    int count_credit=0, count_debit=0;
    char option;
    float balance = 2000;
    float deposit, total_one, total_d;
    float withdraw, total_w, total_two;
    float min_bal;
    printf("Your balance is: %.2f\n\n", balance);
   

    printf("Transaction options: \n");
    printf("1 - Deposit funds (credit transaction) \n");
    printf("2 - Withdraw funds (debit transaction) \n");
    printf("3 - Print statement of account \n");
    printf("4 - Compute interest and exit \n");
   
        while(option!=4){
    printf("Please indicate your option:\t");
    scanf("%d", &option);                     
                       
      if(option==1){
                  printf("\n How much do you want to deposit?\t");
                  scanf("%f", &deposit);
                  total_d+=deposit;
                  total_one= (total_d + balance);
        printf("Your balance is:\t %.2f\n", total_one);
                    //end of option one
                    count_credit++; // counts credit transactions
                    }

       
        else if (option==2){
                      printf("\n How much do you want to withdraw?\t");
                      scanf("%f",&withdraw);
                      total_w=(total_w-withdraw);
                      balance=total_one;
                      total_two=(balance+total_w);                                             
        printf("Your current balance is:\t %.2f\n", total_two);
        count_debit++; //counts debit transactions
                          }//end of option two
        else if (option==3){
                      printf("\n Current balance:\t%.2f\n", balance);
                  min_bal=(balance*1.28);
                      printf("Minimum balance: \t%.2f\n", min_bal);
                          }//end of option three

                          }//end of while statement
//option 4

                 
                    printf("\nStatement of Account:\n\n");
                          printf("Credit Transactions: %d\n", count_credit);
                          printf("Debit Transactions: %d\n", count_debit);
                          printf("Current Balance: \n");
                          printf("Minimum Balance: \n");
                          printf("Interest Computed: \n");
                          printf("Final Balance: \n");
                          printf("\nGood Bye! \n");
         
                   
    system ("pause");
    return 0;
}

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So, strictly speaking, you are not resetting the balance - you just never change it when there is a deposit, and probably not even god knows what the result is of your withdrawal code, you do change the balance, but I'd be surprised if you can withdraw 500 pounds and end up with 1500 as a balance, since you are using variables that haven't been initialized.

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Mats

so how do i initialize them or what can i do to change the balance. i know my code never changes the balance. my code is wrong i just wanted some kind of substance to look at you know? but what should the code look like to do what i need?

I would suggest, instead of initializing the total_w and total_d, you remove them - as they are part of the problem.

Then you update balance as per what salem wrote about 7 or so posts back.

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Mats

haha ur awesome man that actually really helped. i dont think i saw that post because u poseted right after it. i do have a slight problem now though. for some reason it counts the credit transactions and not the debit...
also if i dont choose option 3, the min_bal prints out 0.00. is there anything you can suggest for this? here is the code so far:

Code:

---

#include <stdio.h>


int main(){
    int count_credit=0;
    int count_debit=0;
    char option;
    float balance = 2000;
    float deposit;
    float withdraw;
    float min_bal;
    printf("Your balance is: &#37;.2f\n\n", balance);
   

    printf("Transaction options: \n");
    printf("1 - Deposit funds (credit transaction) \n");
    printf("2 - Withdraw funds (debit transaction) \n");
    printf("3 - Print statement of account \n");
    printf("4 - Compute interest and exit \n");
   
    while(option!=4){
    printf("Please indicate your option:\t");
    scanf("%d", &option);                     
                       
      if(option==1){
                  printf("\n How much do you want to deposit?\t");
                  scanf("%f", &deposit);
                balance+=deposit;
               
        printf("Your balance is:\t %.2f\n", balance);
                    //end of option one
                    count_credit++; // counts credit transactions
                    }

       
        else if (option==2){
                  printf("\n How much do you want to withdraw?\t");
                  scanf("%f", &withdraw);
                balance-=withdraw;
               
        printf("Your balance is:\t %.2f\n", balance);
                    //end of option one
                    count_debit++; // counts debit transactions
                    }

        else if (option==3){
                      printf("\n Current balance:\t%.2f\n", balance);
                  min_bal=balance-(balance*.28);
                      printf("Minimum balance: \t%.2f\n", min_bal);
                          }//end of option three

                          }//end of while statement
//option 4

                 
                    printf("\nStatement of Account:\n\n");
                          printf("Credit Transactions: %d\n", count_credit);
                          printf("Debit Transactions: %d\n", count_debit);
                          printf("Current Balance: %.2f\n", balance);
                          printf("Minimum Balance: %.2f \n", min_bal);
                          printf("Interest Computed: \n");
                          printf("Final Balance: \n");
                          printf("\nGood Bye! \n");
         
                   
    system ("pause");
    return 0;
}

---

I don't really see how you could not count the transactions - the code looks OK to me.

[Nit pick: You have two comments saying "End of option one", neither of which are at the end of an option - the second one not even within option one. Although this is quite obvious in this case, comments that do NOT reflect the actual code is much worse than no comment at all]

Why do you think that min_balance is not presented when you haven't used option three?

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Mats

yeah i noticed the option thing after i posted but i had to go to class. when i choose option 4 automatically, it prints the current balance as 2000 but it says minimum balance 0.00. im not too sure how i can get this to change but i havent really tried yet.
the counter i thought was right too. i have no idea why it wouldnt count the debit transactions but... it doesnt

Counting debit and credit seems to work fine for me.

You really should use int for your "option" variable, as it's currently read as an integer, not as a char, meaning that it overwrites some data beyond the size of the variable (char is one byte, integer is usually 4 bytes, so 3 bytes of something else is overwritten - you may be lucky in this particular instance that the next data item is a float, so it's forced to an alignment of 4 leaving 3 bytes of "filler" in betwen, meaning that you don't get anything useful overwritten, but that's not guaranteed to always be the case).

So, how do you think you should calculate the min_balance correctly?

--
Mats

the min balance i think i calculated correctly. the only problem is if the user chooses option 4 and no other option, the min balance prints out wrong. i calculated the interest and the final balance nicely. i have no idea why the debit counting isnt working for me. i put a print statement in the section and it keeps counting 1 but only prints out 0 here is the latest code i have:

Code:

---

#include <stdio.h>
#define annum .035

int main(){
    int count_credit=0, count_debit=0;
    int option;
    float balance = 2000;
    float deposit, total_one, total_d;
    float withdraw, total_w, total_two;
    float min_bal;
    double interest, final;
    printf("Your balance is: &#37;.2f\n\n", balance);
   

    printf("Transaction options: \n");
    printf("1 - Deposit funds (credit transaction) \n");
    printf("2 - Withdraw funds (debit transaction) \n");
    printf("3 - Print statement of account \n");
    printf("4 - Compute interest and exit \n");
   
        while(option!=4){
    printf("Please indicate your option:\t");
    scanf("%d", &option);                     
                       
      if(option==1){
                  printf("\n How much do you want to deposit?\t");
                  scanf("%f", &deposit);
                  balance+=deposit;
        printf("Your balance is:\t %.2f\n", balance);
                    //end of option one
                    count_credit++; // counts credit transactions
                    }

       
        else if (option==2){
                      printf("\n How much do you want to withdraw?\t");
                      scanf("%f",&withdraw);
                      balance-=withdraw;                                             
        printf("Your current balance is:\t %.2f\n", balance);
        count_debit++; //counts debit transactions
                          }//end of option two
      else if (option==3){
                      printf("\n Current balance:\t%.2f\n", balance);
                  min_bal=balance-(balance*.28);
                      printf("Minimum balance: \t%.2f\n", min_bal);
                          }//end of option three

                          }//end of while statement
//option 4
       
                 
        interest=balance*(annum/12);
        final=interest+balance;
       
                    printf("\nStatement of Account:\n\n");
                          printf("Credit Transactions: %d\n", count_credit);
                          printf("Debit Transactions: %d\n", count_debit);
                          printf("Current Balance:\t %.2f \n", balance);
                          printf("Minimum Balance:\t%.2f \n", min_bal);
                          printf("Interest Computed:\t%.2lf \n", interest);
                          printf("Final Balance:\t %.2f \n", final);
                          printf("\nGood Bye! \n");
         
                   
    system ("pause");
    return 0;
}

---

First of all, I don't think deducting 28 % from the current balance is the right way to calculate the minimum (low water mark) balance as per the problem description you posted.

Quote:

---

... paying interest for the month based on the minimum balance maintained in the account over the month ...

---

. There is no mention of 28% there or anywhere else in the code. Where does 28% come from?

Second, what do you think the minimum balance should be, if we do just option 4, with no other operations on the account? How would you go about achieving that?

I'm not trying to be difficult, I'm just trying to make you think about what the solution should be, because me just telling you what you need to do isn't the right thing - you will not learn from that, and that's what you need to do if you want to succeed with your education...

--
Mats

dont worry man i really apreciate it because this is the only way i will learn. i do have a second program to write but that comes later. i got 28% because in the example he had, it showed $2500 and the min was $1800. thats where i got it from lol. i really have no other idea where to form a minimum with the information given to me. the problem says the balance on january 1st is $2000. i couldnt figure out any other way to find the minimum except by using the example and figuring how much percent was deducted. the problem says:

Quote:

---

Assume that the user will select option 4 exactly once as her last option, i.e., the user selects option 4 after performing all occurrences of options 1, 2, and 3. Also assume that option 4 is selected on the last day of the month, i.e., the user will receive interest for an entire month at this point.

---

i figured if i take the min_bal statment: "min_bal=balance-(balance*.28);" and copy it out of the third option, above the interest calculation. it will print the min balance even if the 3rd option isnt calculated so that fixed that problem. also the interest is taken from the min balance, not the full balance. so i fixed that problem too

so how is the minimum calculated???

> so how is the minimum calculated???
By comparing min_bal with balance, every time you make a withdrawal.

Code:

---

#include <stdio.h>
#define annum .035

int main(){
   
    int count_credit=0, count_debit=0;
    int option;
    float balance = 2000;
    float deposit, total_one, total_d;
    float withdraw, total_w, total_two;
    float min_bal;
    float interest, final;
    printf("Your balance is: $&#37;.2f\n\n", balance);
   
    //the list of transactions
    printf("Transaction options: \n");
    printf("1 - Deposit funds (credit transaction) \n");
    printf("2 - Withdraw funds (debit transaction) \n");
    printf("3 - Print statement of account \n");
    printf("4 - Compute interest and exit \n");
   
        while(option!=4){
    printf("Please indicate your option:\t");
    scanf("%d", &option);                     
                        //if option one was selected
      if(option==1){
                  printf("\n How much do you want to deposit?\t");
                  scanf("%f", &deposit);
                  balance+=deposit;
        printf("Your balance is:\t $%.2f\n", balance);
                   
                    count_credit++; // counts credit transactions
                    }//end of option one

       
        else if (option==2){  //if option 2 was selected
                      printf("\n How much do you want to withdraw?\t");
                      scanf("%f",&withdraw);
                      balance-=withdraw;                                             
        printf("Your current balance is:\t $%.2f\n", balance);
       
        count_debit++; //counts debit transactions                 
                          }//end of option two
                         
      else if (option==3){  //if option 3 was selected
                      printf("\n Current balance:\t $%.2f\n", balance);
                  min_bal=balance-(balance*.28);
                      printf("Minimum balance: \t $%.2f\n", min_bal);
                          }//end of option three

                          }//end of while statement

       
        min_bal=balance-(balance*.28); /*I printed the min_bal statement
                                        outside the third option incase option
                                        4 was selected from the main screen*/         
        interest=min_bal*(annum/12); //computation of the interest
        final=interest+balance;
    //option 4   
                    printf("\nStatement of Account:\n\n");
                          printf("Credit Transactions: %d\n", count_credit);
                          printf("Debit Transactions: %d\n", count_debit);
                          printf("Current Balance:\t $%.2f \n", balance);
                          printf("Minimum Balance:\t $%.2f \n", min_bal);
                          printf("Interest Computed:\t $%.2f \n", interest);
                          printf("Final Balance:\t $%.2f \n", final);
                          printf("\nGood Bye! \n");
         
                   
    system ("pause");
    return 0;
}

---

i think this is the final product. the only thing is the min balance is calculated on a guess because the example the teacher used said if the balance is 2500 then the min balance is 1800... that is 28% of 2500

Update min_bal in option 2, when you update balance with a withdrawal.

Quote:

---

Originally Posted by Salem

Update min_bal in option 2, when you update balance with a withdrawal.

---

i thought the program already updates min_bal when i withdraw.