Committing Brute Force version of program. Failed in CodeChef
Added a new problem solution on checking unique characters in a string
using bit vector.

Also adding unsolved Puzzle at codechef
Added a new program on checking whether one string is a permutation of
the other.
Added a program to encode spaces to %20 to string in form of char array.
Committed two versions of Maximum Sum Subarray. Both work in Linear time
complexity.
Merged Rectquery