General

• As you modify either of the given programs, keep testing them (and saving them!). Do this as you go along.

  That is, each time you have made some kind of single, self-contained, modification, save the file, and try it out if possible. For example, if you have added a new statement, or a declaration of a new variable, then this should, as a minimum, not have introduced any new compile or link time problems. So check that this is the case before going any further. In many cases, you will be able to do even better than this. If you have just introduced a new printf() statement, for example, then you should immediately be able to check that it actually works - that it does print out what it should! And so on.

  In this way the scale of the "current" problems with your program is always kept small and manageable. Whereas, if you make all your modifications before trying any of them, then you are likely to be overwhelmed by the problems, and not know where to even start in trying to solve them.

• Whenever your program is supposed to read data in it is a good idea to have the program immediately print it back out again, before reading anything further. In this way you can separate problems to do with reading the data from problems to do with processing it.

• Sometimes when you have a program running under the Turbo-C++ IDE you may decide, for whatever reason, that you want to terminate it immediately rather than going through whatever procedure is required to get it to finish "naturally". For example, if the program needs to read in 50 numbers, but it already clear that the first has been mis-read, you don't want to bother typing in the remaining 49. Or (as can easily happen) you program may get into an "infinite" loop, such that it will never terminate "naturally". In such circumstances you can usually abort the program by typing Ctrl-Break. That is, press down and hold the Ctrl key (located to the left of the space bar), and then press and release the Break key (also labelled Pause: the Break legend is on the front face of the key; it is located at the right end of the very top row of keys). You may have to do this twice before it will take effect. The program should then be terminated, and control returns to the normal Turbo-C++ IDE environment.