added binary solutions

LeetCode

Author: SanjarH

add_binary.py

@@ -0,0 +1,48 @@
+# Learn Python together
+
+"""Given two binary strings a and b, 
+return their sum as a binary string."""
+
+# Solution 
+# we can use bin function and change types
+def addBinary(a:str, b:str) -> str:
+    return str(bin(int(a, 2) + int(b, 2)))[2:]
+            
+# check    
+print(addBinary("1010",'1011')) # Output -> 10101
+print(addBinary('0','0')) # Output -> 0
+print(addBinary('0','1')) # Output -> 1
+
+
+def addBinary2(a:str, b:str) -> str:
+    
+    carryover = 0
+    result = ""
+
+    # using for loop and max function to iterate 
+    # through the strings starting from the last index
+    for i in range(max(len(a), len(b))): 
+
+        # geting the numbers at the current index of each string, or 0 if beyond the limit
+        a_num = int(a[::-1][i]) if i < len(a) else 0
+        b_num = int(b[::-1][i]) if i < len(b) else 0
+
+        # sum of numbers and carryover
+        total = a_num + b_num + carryover
+
+        # result would be the rest of total divided by 2 + result that was before 
+        result = str(total % 2) + result
+
+        # carryover is 1 if total is greater than 1, otherwise 0 
+        carryover = 1 if total > 1 else 0
+
+    # add any remaining carryover to the beginning of result 
+    if carryover == 1: 
+        result = "1" + result 
+
+    return result
+
+# check
+print(addBinary2("1010",'1011')) # Output -> 10101
+print(addBinary2('0','0')) # Output -> 0
+print(addBinary2('0','1')) # Output -> 1