# way to check 3 elements of array and set 4th

• 01-09-2006
Syneris
way to check 3 elements of array and set 4th
I'm trying to think of how I can check 3 elements of a 4 element array and set the 4th. I have a bool array of 4 elements that all start off false. If any 3 of the elements are true, the other element needs to be set to true also. If only 1 or 2 elements are true, nothing is changed.
• 01-09-2006
laserlight
That would be rather simple, methinks. What code have you written so far in your attempt to solve your problem?

EDIT:
Quote:

If any 3 of the elements are true, the other element needs to be set to true also. If only 1 or 2 elements are true, nothing is changed.
Surely you mean "if all 3 of the other elements are true", otherwise you have conflicting requirements, or?
• 01-09-2006
ZuK
Code:

```  bool arr[4];   int nrs = 0, ns;   for ( int idx = 0; idx < 4; idx ++ ) {       if ( arr[idx] ) nrs ++;       else ns = idx;   }   if ( nrs == 3 ) arr[ns]=true;```
Don't know if that is what you want.
this checks if any 3 of the 4 are set if yes sets the 4th as well
Kurt
• 01-09-2006
Syneris
Thanks Zuk, that looks like exactly what i was wanting. I was over thinking the simplicity of it