primitive multiply (py)

Author: jsgoller1

elements-of-programming-interviews/problem_mapping.js

@@ -80,7 +80,7 @@ problem_mapping = {
                 "total": 10006
             },
             "Python: primitive_multiply.py": {
-                "passed": 0,
+                "passed": 10006,
                 "total": 10006
             }
         },

elements-of-programming-interviews/python/primitive_multiply.py

@@ -1,9 +1,25 @@
 from test_framework import generic_test
 
 
+def add(x: int, y: int) -> int:
+    val = x ^ y
+    carry = (x & y) << 1
+    while carry:
+        x = val
+        y = carry
+        val = x ^ y
+        carry = (x & y) << 1
+    return val
+
+
 def multiply(x: int, y: int) -> int:
-    # TODO - you fill in here.
-    return 0
+    product = 0
+    while y:
+        if (y & 1):
+            product += x
+        x <<= 1
+        y >>= 1
+    return product
 
 
 if __name__ == '__main__':