added abc_create_word

Author: Pl4tt

python/datastructures/dijkstra.py

@@ -1,4 +1,4 @@
-from collections import namedtuple, defaultdict
+from collections import defaultdict
 
 
 class Graph:

python/dynamic_programming/abc_create_word.py

@@ -0,0 +1,38 @@
+def recursive_is_valid(s, t=None, memo=None):
+    if memo is None:
+        memo = {}
+    if t is None:
+        t = ""
+
+    if t in memo:
+        return memo[t]
+    if s == t:
+        return True
+    if len(t) > len(s):
+        return False
+    
+    for i in range(len(t)+1):
+        new_t = t[:i+1] + "abc" + t[i+1:]
+        
+        if recursive_is_valid(s, new_t, memo):
+            memo[t] = True
+            return True
+    
+    memo[t] = False
+    return False
+
+def fast_is_valid(s):
+    while "abc" in s:
+        s = s.replace("abc", "")
+    
+    return not s
+
+
+
+
+
+if __name__ == "__main__":
+    print(fast_is_valid("aabcbc"))  # True
+    print(fast_is_valid("abcabcababcc"))  # True
+    print(fast_is_valid("abccba"))  # False
+    print(fast_is_valid("abcabcabcabcabcabcabcabcabcabc"))  # True