The Parenthesis Balance problem, though a simple one to solve, gave me lot of WAs. I wanted to solve it without using a stack at first, using the same input string that the parenthesis is scanned into. After 6-8 WAs, I finally gave up and wrote a stack using an array. I still got a WA! Now, this is something I'd suspected earlier on, but lazed about fixing it. Finally, the fix was simple and I tried to post this onto the UVa forum, but the forum is refusing to log me in for some reason.
Although the problem statement says that the we can assume that the string size will not exceed 128, we ought to consider that there may be trailing spaces exceeding 128 after the no of test cases are given! Now this seems like a deliberate thing that the UVa guys have done as one of their tricks. :) Of course, this is not an issue if you're using C++ I/O calls and cin.ignore(), but for C I/O calls, most likely you're using gets(), getline() or the safer, fgets(), unless, worse yet, you used a getchar()! In any case, if you're lazy like me, you'd be using the same character array that you've reserved for reading the input parenthesis string. And if that, the size needs to be more than 129 (one that you will have definitely added for newline character). After multiple failures, I changed the size to 1024 and both, the stack as well as non-stack version got AC. :)
Cheers! C++, ... er, C you around. :P
Although the problem statement says that the we can assume that the string size will not exceed 128, we ought to consider that there may be trailing spaces exceeding 128 after the no of test cases are given! Now this seems like a deliberate thing that the UVa guys have done as one of their tricks. :) Of course, this is not an issue if you're using C++ I/O calls and cin.ignore(), but for C I/O calls, most likely you're using gets(), getline() or the safer, fgets(), unless, worse yet, you used a getchar()! In any case, if you're lazy like me, you'd be using the same character array that you've reserved for reading the input parenthesis string. And if that, the size needs to be more than 129 (one that you will have definitely added for newline character). After multiple failures, I changed the size to 1024 and both, the stack as well as non-stack version got AC. :)
Cheers! C++, ... er, C you around. :P
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