[search] Improved klotski.py with deque and set to gain better performance
Simplified on level of transform from list to tuple
[search] fixed a typo
Added *.eps to .gitignore
[list] Added circular list problem
[circular list] Explained the circular list detection method
[circular list] Added ANSI C example program to detect circular list
[circular list] Described the detection program
[circular list] Described the detection program
[circular list] Solved the problem of where the loop starts
[circular list] Added ANSI C program to locate the node where loop starts
[circular list] completed
[circular list] Fixed some mistakes
[circular list] Some editorial work
[problems] Added a problem about stack
[circular list] fixed a typo
[circular list] Added more cases analysis
[circular list] Added reference to Brend's algorithm
[Circular list] Added another pure circular detection method
[Circular list] Editorial work