compound intrest program(beginner)

[c_beginner]

yes, this is my how work question. Since I am lack in getting
an assistance with my lab work I put this in this advance group.
Sorry for the trouble I am making.

Write a program to calculate the compound interest.

#include<stdio. h>
#include<stdlib .h>
double intrest(double tot_amount,floa t percent)
{
double temp;
if(percent < 0.0 || percent > 100.0)
{
printf("un-reasonable intrest rate, enter again\n");
fscanf(stdin,"% f",percent);
}
temp = (tot_amount * percent) / 100;
return temp;
}
int main(void)
{
double intrest_rate,cp nd_intrest,prnc _amount,percent ;
unsigned short year,i;
printf("enter the percent of intrest,amount, year\n");
fscanf(stdin,"% f%f%d",&percent ,&prnc_amount,& year);
if(year > 50)
{
printf("kindly input the reasonable year of return\n");
fscanf(stdin,"% d",&year);
}
else
{
intrest_rate = intrest(prnc_am ount,percent);
cpnd_intrest = prnc_amount*(1+ intrest_rate);
for(i = year ; i< year ; i++)
cpnd_intrest = cpnd_intrest * i;
}
printf("the compound intrest is %f\n",cpnd_intr est);
return 0;
}

I am getting a strange output when I run the program.Kindly help.

[Eric Sosman]

Re: compound intrest program(beginne r)



c_beginner wrote On 02/16/06 10:44,:[color=blue]
> [...]
> int main(void)
> {
> double intrest_rate,cp nd_intrest,prnc _amount,percent ;
> unsigned short year,i;
> printf("enter the percent of intrest,amount, year\n");
> fscanf(stdin,"% f%f%d",&percent ,&prnc_amount,& year);[/color]

Here's at least one problem (I haven't looked carefully
for others): the conversion specifiers in the format string
don't match the corresponding pointer arguments. With "%f"
you're telling fscanf() to produce a `float', but you've
supplied pointers to `double' variables instead. Similarly,
"%d" tells fscanf() to produce an `int', but you've provided
a pointer to an `unsigned short'. fscanf() trusts you (not
the best policy, it appears ;-), and when it tries to store
`float' values in `double' variables or an `int' value in
an `unsigned short' variable, there's no telling what will
happen.

Hint #1: Go back to your C textbook and read the scanf()
section again. Although the format strings look similar to
those used with printf(), they are *not* the same at all.

Hint #2: Some compilers are able to detect and warn
about mismatches of this kind, if you ask them to do so.
For example, if you're using gcc try the "-W -Wall" flags
when you compile your code. Other compilers that can do
this have their own incantations; consult the documentation.

--
Eric.Sosman@sun .com

[Mara Guida]

Re: compound intrest program(beginne r)

c_beginner wrote:[color=blue]
> yes, this is my how work question. Since I am lack in getting
> an assistance with my lab work I put this in this advance group.
> Sorry for the trouble I am making.
>
> Write a program to calculate the compound interest.
>
> #include<stdio. h>
> #include<stdlib .h>
> double intrest(double tot_amount,floa t percent)
> {
> double temp;
> if(percent < 0.0 || percent > 100.0)
> {
> printf("un-reasonable intrest rate, enter again\n");
> fscanf(stdin,"% f",percent);
> }
> temp = (tot_amount * percent) / 100;
> return temp;
> }
> int main(void)
> {
> double intrest_rate,cp nd_intrest,prnc _amount,percent ;
> unsigned short year,i;
> printf("enter the percent of intrest,amount, year\n");
> fscanf(stdin,"% f%f%d",&percent ,&prnc_amount,& year);[/color]
You have a type mismatch: %f <= float; percent <= double
You have a type mismatch: %f <= float; prnc_amount <= double
You have a type mismatch: %d <= int; year <= unsigned short
[color=blue]
> if(year > 50)
> {
> printf("kindly input the reasonable year of return\n");
> fscanf(stdin,"% d",&year);[/color]
You have a type mismatch: %d <= int; year <= unsigned short
[color=blue]
> }
> else
> {
> intrest_rate = intrest(prnc_am ount,percent);
> cpnd_intrest = prnc_amount*(1+ intrest_rate);
> for(i = year ; i< year ; i++)[/color]
The body of the for loop is never executed
[color=blue]
> cpnd_intrest = cpnd_intrest * i;
> }
> printf("the compound intrest is %f\n",cpnd_intr est);
> return 0;
> }
>
> I am getting a strange output when I run the program.Kindly help.[/color]


Set your compiler to output warning messages and treat them as errors.
Correct the errors/warnings and rerun the program.

[August Karlstrom]

Re: compound intrest program(beginne r)

c_beginner wrote:[color=blue]
> yes, this is my how work question. Since I am lack in getting
> an assistance with my lab work I put this in this advance group.
> Sorry for the trouble I am making.
>
> Write a program to calculate the compound interest.
>
> #include<stdio. h>
> #include<stdlib .h>
> double intrest(double tot_amount,floa t percent)
> {
> double temp;
> if(percent < 0.0 || percent > 100.0)
> {
> printf("un-reasonable intrest rate, enter again\n");
> fscanf(stdin,"% f",percent);
> }
> temp = (tot_amount * percent) / 100;
> return temp;
> }
> int main(void)
> {
> double intrest_rate,cp nd_intrest,prnc _amount,percent ;
> unsigned short year,i;
> printf("enter the percent of intrest,amount, year\n");
> fscanf(stdin,"% f%f%d",&percent ,&prnc_amount,& year);
> if(year > 50)
> {
> printf("kindly input the reasonable year of return\n");
> fscanf(stdin,"% d",&year);
> }
> else
> {
> intrest_rate = intrest(prnc_am ount,percent);
> cpnd_intrest = prnc_amount*(1+ intrest_rate);
> for(i = year ; i< year ; i++)
> cpnd_intrest = cpnd_intrest * i;
> }
> printf("the compound intrest is %f\n",cpnd_intr est);
> return 0;
> }
>
> I am getting a strange output when I run the program.Kindly help.[/color]

Why do you post the same question twice? I think you should instead
thank Antonio for the help you got with your previous posting.


August

--
I am the "ILOVEGNU" signature virus. Just copy me to your
signature. This email was infected under the terms of the GNU
General Public License.

[Antonio Contreras]

Re: compound intrest program(beginne r)

August Karlstrom wrote:[color=blue]
> c_beginner wrote:[color=green]
> > yes, this is my how work question. Since I am lack in getting
> > an assistance with my lab work I put this in this advance group.
> > Sorry for the trouble I am making.
> >
> > Write a program to calculate the compound interest.
> >[/color][/color]

<snip actual code>
[color=blue][color=green]
> > I am getting a strange output when I run the program.Kindly help.[/color]
>
> Why do you post the same question twice? I think you should instead
> thank Antonio for the help you got with your previous posting.[/color]

Actually the program is not exactly the same and he took into account
some things I said (he changed some variables from float to double and
added some code after my hints). This program also claims to compute a
compound interest, the other one claimed to compute a simple interest.
(And I say claimed because I did not check the program logic.)

Anyway you're right in saying that some kind of acknowledgement
would've been nice.

[hammrGRS@hotmail.com]

Re: compound intrest program(beginne r)


c_beginner wrote:[color=blue]
> yes, this is my how work question. Since I am lack in getting
> an assistance with my lab work I put this in this advance group.
> Sorry for the trouble I am making.
>
> Write a program to calculate the compound interest.
>
> #include<stdio. h>
> #include<stdlib .h>
> double intrest(double tot_amount,floa t percent)
> {
> double temp;
> if(percent < 0.0 || percent > 100.0)
> {
> printf("un-reasonable intrest rate, enter again\n");[/color]
printf("Invalid rate you dolt. Try again
nimrod\n");[color=blue]
> fscanf(stdin,"% f",percent);
> }
> temp = (tot_amount * percent) / 100;
> return temp;
> }
> int main(void)
> {
> double intrest_rate,cp nd_intrest,prnc _amount,percent ;
> unsigned short year,i;
> printf("enter the percent of intrest,amount, year\n");
> fscanf(stdin,"% f%f%d",&percent ,&prnc_amount,& year);
> if(year > 50)
> {
> printf("kindly input the reasonable year of return\n");[/color]
printf("please please please enter the year of
return\n");
printf("please? n");[color=blue]
> fscanf(stdin,"% d",&year);
> }
> else
> {
> intrest_rate = intrest(prnc_am ount,percent);
> cpnd_intrest = prnc_amount*(1+ intrest_rate);
> for(i = year ; i< year ; i++)
> cpnd_intrest = cpnd_intrest * i;
> }
> printf("the compound intrest is %f\n",cpnd_intr est);
> return 0;
> }
>
> I am getting a strange output when I run the program.Kindly help.[/color]

That should correct the output problems.

[Martin Ambuhl]

Re: compound intrest program(beginne r)

c_beginner wrote:[color=blue]
> yes, this is my how work question. Since I am lack in getting
> an assistance with my lab work I put this in this advance group.
> Sorry for the trouble I am making.[/color]

See if this much shorter program helps you figure out your problems.
Note specifically that many of your scanf specifiers are wrong.

#include <stdio.h>
#include <math.h>

int main(void)
{
double principal, rate, periods;
printf("enter interest rate per period, principal amount,\n"
" & number of periods, separated by spaces: ");
fflush(stdout);
scanf("%lf%lf%l f", &rate, &principal, &periods);
printf("the compound interest is %f\n",
principal * (pow(1 + rate / 100, periods) - 1));
return 0;
}