For loop cumulative calculation problem. C programming - c

Question

Here I have created a compounding interest calculator. The user inputs principal, interest% and duration (in quarters). I have used a for loop for the initial calculation. But, I don't know how to get the total to rollover to the next quarter's principal.
Say the user inputs 1000, 5% and 2 quarters. The output should look like, Q1 Principal=$1000, Interest=0.05, Total=$1012.50, Q2 =$1012.50 =0.05 =$1025.16
Also my last Do while is giving me some issues. The ouput is spitting out a couple extra lines before letting the user start over.
Any advice would be greatly appreciated.
Thank you
#include <stdio.h>
int main (void)
{
int a = 0, b=0;
double interest, prin, total=0;
char check = ' ';
do{
do{
do{
printf (" Please enter principal:\n");
scanf ("%lf", &prin);
}while(prin <=0);
do{
printf ("Please enter desired interest greater
than 0 less than 20 :\n");
scanf ("%lf", &interest);
}while(interest <=0 || interest >20);
interest = interest/100;
do{
printf ("For how many quarters would you like
to deposit: (more than 0, less than 40) \n");
scanf ("%d", &b);
}while(b <=0 || b >40);
printf ("Is this information correct? Press X
to continue" );
scanf ("\n%c", &check);
}while(check != 'x' && check != 'X');
total = prin * (1+(interest *.25));
printf ("Quarter Principal Interest
Total\n");
for(a=1; ;++a){
printf ("%2d $%.2f %.2lf
$%.2lf\n", a, prin, interest, total);
if(a == b)
break;
}
printf ("Do you want to start over (Y/N)?");
scanf ("%c\n", &check);
}while(check != 'y' || check != 'Y');
return 0;
}

Answer 1

The are some problem with indentation and logic in your code. You need to updade principle in for loop statement. Then print it out .Here is my solution
#include <stdio.h>
int main(void)
{
int a = 0, b = 0;
double interest, prin, total = 0;
char check = ' ';
do {
do {
do {
printf(" Please enter principal:\n");
scanf("%lf", &prin);
} while (prin <= 0);
do {
printf("Please enter desired interest greater than 0 less than 20 :\n");
scanf("%lf", &interest);
} while (interest <= 0 || interest > 20);
interest = interest / 100;
do {
printf("For how many quarters would you like to deposit : (more than 0, less than 40) \n");
scanf("%d", &b);
} while (b <= 0 || b > 40);
printf("Is this information correct? Press X to continue" );
scanf("\n%c", &check);
} while (check != 'x' && check != 'X');
printf("Quarter Principal Interest Total\n");
for (a = 1; a<=b; ++a) {
total = prin * (1 + (interest *.25));
printf("%2d $%.2f %.2lf $%.2lf\n", a, prin, interest, total);
prin = total;
}
printf("Do you want to start over (Y/N)?");
scanf("%c\n", &check);
} while (check != 'y' || check != 'Y');
return 0;
}