Update edit_distance.py

algorithmic_toolbox/week_5/04_dynamic_programming_starter_files/edit_distance/edit_distance.py

@@ -1,7 +1,37 @@
-# Uses python3
-def edit_distance(s, t):
-    #write your code here
-    return 0
-
+# A Dynamic Programming based Python program for edit 
+# distance problem 
+def editDistDP(str1, str2, m, n): 
+    # Create a table to store results of subproblems 
+    dp = [[0 for x in range(n + 1)] for x in range(m + 1)] 
+
+    # Fill d[][] in bottom up manner 
+    for i in range(m + 1): 
+        for j in range(n + 1): 
+
+            # If first string is empty, only option is to 
+            # insert all characters of second string 
+            if i == 0: 
+                dp[i][j] = j    # Min. operations = j 
+
+            # If second string is empty, only option is to 
+            # remove all characters of second string 
+            elif j == 0: 
+                dp[i][j] = i    # Min. operations = i 
+
+            # If last characters are same, ignore last char 
+            # and recur for remaining string 
+            elif str1[i-1] == str2[j-1]: 
+                dp[i][j] = dp[i-1][j-1] 
+
+            # If last character are different, consider all 
+            # possibilities and find minimum 
+            else: 
+                dp[i][j] = 1 + min(dp[i][j-1],        # Insert 
+                                   dp[i-1][j],        # Remove 
+                                   dp[i-1][j-1])    # Replace 
+
+    return dp[m][n] 
 if __name__ == "__main__":
-    print(edit_distance(input(), input()))
+    str1=input()
+    str2=input()
+    print(editDistance(str1, str2,len(str1),len(str2)))