Thread: How to find first bad number from float

Hi.I have this problem : I am entering numbers to float ... I want program to find out, which first number is not from specific interval. How to do it ? Example: Enter input : 5 10 20 30 50 46 . 30 is invalid. Here is the code :

Code:

while(scanf("%f",&input)!=EOF || input==0)
{
sum=input+sum;
if (getchar() == '\n') break;
};        //user input ended with enter/0

if(input!=100 ||input!=50 ||input!=20 ||input!=10 ||input!=5 ||input!=2  ||input!=1 ||input!=0.5 ||input!=0.2 ||input!=0.1 ||input!=0.05 ||input!=0.02 ||input!=0.01) 
printf("%f is invalid\n",input);

Any help appreciated

You should be validating your input inside the loop, after each read, presumably before adding it to "sum".

Code:

if(input!=100 ||input!=50 ||input!=20 ||input!=10 ||input!=5 ||input!=2  ||input!=1 ||input!=0.5 ||input!=0.2 ||input!=0.1 ||input!=0.05 ||input!=0.02 ||input!=0.01)

Your logic is flawed ... this will always be true.

For instance, if "input" is 100, then "input!=50" is true, and since you're logic OR'ing, the whole expression will be true.

You can make your validation much nicer with a simple loop and array - I'll leave the implementation up to you. I'd also strongly recommend putting your validation code in a separate function and returning a success/fail value (and react accordingly in the calling code).

It looks like you have the basic idea of the array/loop setup, but it's still not entirely correct. Also, you're still validating the numbers after the loop has ended. There are a few other issues with the code, also, but I figured we'd tackle them a few at a time.

At this point, you should post your entire program (or if it's pretty big, just a simplified yet complete version we can compile and run ourselves).