solve spelling and grammar problems

README.md

@@ -1,15 +1,16 @@
 # common_algorithms_and_data_structures
-these are the most common algorithms and data structures which i think every programmer should know
+
+these are the most common algorithms and data structures that I think every programmer should know
 
 If you are new to programming, then this repo is your starting point to become a better programmer.
 
-# how to use this repository ?
+# how to use this repository?
 
-According to the list below, start reading readme of each part and try to write a code for that algorithm or data structure. After that (or if you couldn't write the code yourself) check my codes.
+According to the list below, start reading the readme of each part and try to write a code for that algorithm or data structure. After that (or if you couldn't write the code yourself) check my codes.
 
-If your code is better than mine or yours is in another language that is not exists in here, please create a pull request and add your codes.
+If your code is better than mine or yours is in another language that does not exist here, please create a pull request and add your codes.
 
-Also if you know another algorithm or data structure which was not in here, create a pull request and add it to this repo.
+Also if you know another algorithm or data structure that was not in here, create a pull request and add it to this repo.
 
 I will be happy while merging pull requests :)
 
@@ -43,8 +44,12 @@ I will be happy while merging pull requests :)
  - [Graph shortest path (BFS)](./path_finding_algorithms/bfs_shortest_path.py)
 
 
-# Refrences
+# Contributing
+
+Feel free :)
+
+# References
 
-The main refrence is this book :
+The main reference is this book :
 
 ![Introduction to algorithms](./docs/intro_to_algos.jpg)