Merge pull request #3 from Qiki/Objective_C

Quick find in Objective C
quick union in Objective C
Merge pull request #4 from Qiki/Objective_C

Quick union in Objective C
implement weighted quick union
Merge pull request #5 from Qiki/Objective_C

implement weighted quick union
Fixed the find root method in the quick union and weighted quick union
Merge remote-tracking branch 'upstream/master' into ROOT_METHOD_REVISED
Merge pull request #6 from Qiki/ROOT_METHOD_REVISED

Find root method fixed