# Computation Loop and duplicate entry error

• 04-28-2010
digitaldan
Computation Loop and duplicate entry error
I'm stuck! Here is problem I am having: The loop I have made calculates values based off an integer value entered by the user from the keyboard where if they enter the same value from a given interval a warning message is displayed followed by a return to the beginning of the loop.

Here is my code so far:

Code:

``` #include <stdio.h> #include <math.h> int main(void) {         int x;         double A, B, C, f1, f2, f3;         printf("Enter a value for A, B, and C:\n");         scanf("%lf %lf %lf", &A, &B, &C);         printf("A = %g \tB = %g \tC = %g\n", A, B, C);         printf("Enter a value for x:\n");         scanf("%d", &x);         printf("x = %d\n",x);                 if(x<=0){                 printf("Case 1\n");                 f1 = (A * pow(x, 3)) - (B * pow(x, 2)) + (x / 1.25);                 printf("Value of x = %3d and y = %6.2f\n", x, f1);                 }         else if(0<x<1){                 printf("Case 2\n");                 f2 = A * x - B * pow(x, 4) + pow(C, 2);                 printf("Value of x = %3d and y = %6.2f\n", x, f2);                 }         else if(x>=1){                 printf("Case 3\n");                 f3 = A * log(x) - B / x - 2 * A;                 printf("Value of x = %3d and y = %6.2f\n", x, f3);                 } }```
Very simple and basic code, as this is my first C/C++ class. The loop works great but I don't know where to go from here to create the additional inputs with the warning message and return to the beginning of the loop.

i hope what I am saying is making sense, I am going on about 4 hours sleep and being up for almost 20 hours at this point (gotta love being a student!).

Any help would be greatly appreciated.

-Dan
• 04-28-2010
NeonBlack
I think you'd better get some rest.

First of all, there's no loop in the code you posted.

Code:

`else if(0<x<1){`
If you want to check it x is between 0 and 1 you do
Code:

`if (0<x && x<1)`
but since you declared x as an int, x can be 0, it can be 1, but it can't be between 0 and 1.