Error: control may reach end of non-void function in C

You are getting this error because if your for loop breaks due to breaking condition i < n; then it don't find any return statement after for loop (see the below, I mentioned in code as comment).

for (int i = 0; i < n; i++){    if (values[i] == value){        return true;        break;    }    else{         return false;    }}  // here you should add either return true or false     }

If for loop break due to i >= n then control comes to the position where I commented and there is no return statement present. Hence you are getting an error "reach end of non-void function in C".

Additionally, remove break after return statement. if return executes then break never get chance to execute and break loop.

   return true;  -- it returns from here.     break;  -- " remove it it can't executes after return "

Check your compiler should give you a warning - 'unreachable code'.

That compiler warning is not correct. Anyway, there is a bigger problem with your code:

bool search(int value, int values[], int n) {    if (n < 1) {        return false;    }       for (int i = 0; i < n; i++) {        if (values[i] == value) {            return true;            break;        }        else {            // !            return false; // ! <-- Here is the mistake.        }                 // !    }    }

This code only checks values[0] == value and then always returns. It's happening because of that else {return false;}.

You should write it this way:

bool search(int value, int values[], int n) {    if (n < 1) {        return false;    }       for (int i = 0; i < n; i++) {        if (values[i] == value) {            return true;            // break;  <- BTW, it's redundant.        }    }        return false;}

Now, function checks entire values array and then returns false if there was no matches. But if it found a match, it will instantly return true witout checking other elements.

Also, compiler will not emit a warning for this code.

Your code is equivalent to

return (n > 0 && values [0] == value);

Either you are in the habit of writing very simple things in an excessively complicated way, or that code doesn't do what you want it to do.