a problem where OO seems more natural to me, implementing a utility class not instantiable. how to prevent instantiation, thanks to http://stackoverflow.com/questions/10558393/prevent-instantiation-of-an-object-outside-its-factory-method/10558404#105…
A + B Problem Too Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 13465    Accepted Submission(s): 10008 Problem Description This problem is also a A + B problem,but it has a little difference,…
use sentinel to avoid boudary testing, use swap trick to avoid extra copy. original version #include <cstdio> #include <algorithm> int main() { //freopen("input.txt","r",stdin); const int MAXSIZE=22, dimSize=20; int bacnums…
Largest Rectangle in a Histogram Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 11706    Accepted Submission(s): 3219 Problem Description A histogram is a polygon composed of a sequence of rec…
Tempter of the Bone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 70032    Accepted Submission(s): 19286 Problem Description The doggie found a bone in an ancient maze, which fascinated him a…
FatMouse' Trade Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 42953    Accepted Submission(s): 14336 Problem Description FatMouse prepared M pounds of cat food, ready to trade with the cats g…
Drainage Ditches Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 8861    Accepted Submission(s): 4141 Problem Description Every time it rains on Farmer John's fields, a pond forms over Bessie's…
Uncle Tom's Inherited Land* Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 1869    Accepted Submission(s): 777 Special Judge Problem Description Your old uncle Tom inherited a piece of land fr…
one recursive approach to solve hdu 1016, list all permutations, solve N-Queens puzzle. reference: the video of stanford cs106b lecture 10 by Julie Zelenski https://www.youtube.com/watch?v=NdF1QDTRkck // hdu 1016, 795MS #include <cstdio> #include &l…
for the backtracking part, thanks to the video of stanford cs106b lecture 10 by Julie Zelenski for the nice explanation of recursion and backtracking, highly recommended. in hdu 2553 cout N-Queens solutions problem, dfs is used. // please ignore, bel…