added string cutting code in python

Author: shiv

string_cutting.py

@@ -0,0 +1,34 @@
+#-*-coding:utf8;-*-
+#qpy:3
+#qpy:console
+
+costs = {'a':1,
+        'b':1,
+        'c':1,
+        'aba':2,
+        'caa':2,
+        'baac':3}
+import time
+start = time.time()
+
+# minimum string cost
+# very similar to rod cutting
+
+tabular = {}
+def solve(s):
+    if s in tabular: return tabular[s]
+    if len(s) == 1 and s in costs:
+        tabular[s] = costs[s]
+        return tabular[s]
+    if len(s) < 1: return 0
+    c=[]
+    for i in range(len(s)):
+        if s[-i:] in costs:
+           c.append(solve(s[:-i])+costs[s[-i:]])
+    print(s, min(c), c)
+    tabular[s] = min(c)
+    return tabular[s]
+
+ans= solve('abaacaabaac')
+print(ans)
+print('solved in:', time.time()-start)