Problems with C++

I'm trying now to write one of my first programs in C++ language. I also tried to do this in C, but had the same problem with that. I tried to make a program, which can convert an int in decimal to a number in an other numeral system. I think the value of x variable changes in the if statement although I wanted to change the value of an element in the array. If you have a look at the input, you can see, that the same expression gives you another value after the if-else statement. Can you help me with that?