Add coin change example; Update README

Author: sarangbishal

README.md

@@ -1,5 +1,8 @@
 # Recursion Visualiser  
-Recursion visualiser is a python tool that draws recursion tree for recursive function with very less code changes.  
+Recursion visualiser is a python tool that visualizes recursion tree with animation and draws recursion tree for recursive function.
+It works with almost any type of recursive function.
+Just add the recursion-visualiser decorator to your function and let it do the rest of the work.
+
 
   ## Installation  
 The only dependency for recursion visualiser is Graphviz which you can download from [here](https://www.graphviz.org/download/)  
@@ -84,6 +87,9 @@ This is taken from one of my answers on quora where I had to manually  draw recu
  - [x] Minimal working version  
  - [x] Upload package to pypi  
  - [x] Support animation
+ - [ ] Support aliasing for function name
+ - [ ] Show repeated states
+ - [ ] Support node_color, backgroundcolor etc
  - [ ] Refactor  
  - [ ] Handle base cases  
  - [ ] Make more beautiful trees

examples/coin_change.gif

@@ -0,0 +1,30 @@
+# Author: Bishal Sarang
+from visualiser.visualiser import  Visualiser as vs
+
+"""
+    Number of ways to make change:
+"""
+@vs(ignore_args=["coins"], show_argument_name=False)
+def f(coins, amount, n):
+    if amount == 0:
+        return 1
+
+    if amount < 0:
+        return 0
+
+    if n <= 0 and amount >= 1:
+        return 0
+
+    include = f(coins=coins, amount=amount - coins[n - 1], n=n)
+    exclude = f(coins=coins, amount=amount, n=n-1)
+
+    return include + exclude
+
+def main():
+    amount = 5
+    coins = [1, 2, 5]
+    print(f(coins=coins, amount=amount, n=len(coins)))
+    vs.make_animation("coin_change.gif", delay=3)
+
+if __name__ == "__main__":
+    main()

examples/coin_change.png

@@ -36,5 +36,4 @@ def f(sum, ans):
 
 # Call solve with sum and an empty list
 f(sum=sum, ans=[])
-# Save recursion tree to a file
-vs.make_animation("make.gif", delay=2)
+vs.write_image("make_sum.png")