First commit

.gitignore

+# ### OSX  ######
+# General 
+.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must end with two \r
+Icon
+
+# Thumbnails
+._*
+
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+.com.apple.timemachine.donotpresent
+
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+
+# ### Windows  ######
+# Windows thumbnail cache files
+Thumbs.db
+Thumbs.db:encryptable
+ehthumbs.db
+ehthumbs_vista.db
+
+# Dump file
+*.stackdump
+
+# Folder config file
+[Dd]esktop.ini
+
+# Recycle Bin used on file shares
+$RECYCLE.BIN/
+
+# Windows Installer files
+*.cab
+*.msi
+*.msix
+*.msm
+*.msp
+
+# Windows shortcuts
+*.lnk
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Algorithms/README.md

+# Algorithms track
+
+These are the topic of algorithms track [see algorithms track](https://www.hackerrank.com/domains/algorithms)
+
+
+1. Warmup
+2. Implementation
+3. Strings
+4. Sorting
+5. Search
+6. Graph Theory
+7. Greedy
+8. Dynamic Programming
+9. Constructive Algorithms
+10. Bit Manipulation
+11. Recursion
+12. Game Theory
+13. NP Complete
+14. Debugging
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DataStructure/README.md

+# Data structure track
+
+These are the topic of data structures track [see data structures track](https://www.hackerrank.com/domains/data-structures)
+
+1. Arrays
+2. Linked Lists
+2. Trees
+3. Balanced Trees
+4. Stacks
+5. Queues
+6. Heap
+7. Disjoint Set
+8. Multiple Choice
+9. Trie
+10. Advanced
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Mathematics/README.md

+# Mathematics track
+
+These are the topic of mathematics track [see mathematics track](https://www.hackerrank.com/domains/mathematics)
+
+
+1. Fundamentals
+2. Number Theory
+3. Combinatorics
+4. Algebra
+5. Geometry
+6. Probability
+7. Linear Algebra Foundations
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README.md

-# Bacal
+# Welcome to Bacal (Back to algorithms)
 
 The Bacal repository to submit problems solutions and track progress.
+
+# How to
+
+Each bacal meeting as group, are going to choose a problem from [hackerrank](https://www.hackerrank.com/dashboard)
+
+Let say teh group choose "2D Array - DS" from a track. [see the challenge](https://www.hackerrank.com/challenges/2d-array/problem)
+
+In the repository i going to create a folder, with name of the problem.
+
+> DataEstructure/2D_Array_DS 
+
+Then for each submission, let say "Felipe submit a solution in Java"
+
+> DataEstructure/2D_Array_DS/Java/ftalavera/problem.java
+
+Then i submit a solution in ruby, will be 
+
+> DataEstructure/2D_Array_DS/Ruby/ravaria/problem.rb
+
+
+## Tracks in hacker Rank
+
+[Algorithms](https://www.hackerrank.com/domains/algorithms)
+
+[Data structures](https://www.hackerrank.com/domains/data-structures)
+
+[Mathematics](https://www.hackerrank.com/domains/mathematics)
+