I'm creating a binary addition algorithm in python. from the output I'm getting it seems as though the binary strings are getting inverted and added that way. I can't seem to figure out what's causing this.
def addBinary(x, y):
carry = False
result = ''
for i in range(len(x)):
if carry == True:
if x[i] == '1' and y[i] == '1':
result = '1' + result
if x[i] =='1' and y[i] == '0':
result = '0' + result
if x[i] =='0' and y[i] == '1':
result = '0' + result
if x[i] == '0' and y[i] == '0':
result = '1' + result
carry = False
else:
if x[i] == '1' and y[i] == '1':
result = '0' + result
carry = True
if x[i] =='1' and y[i] == '0':
result = '1' + result
if x[i] =='0' and y[i] == '1':
result = '1' + result
if x[i] == '0' and y[i] == '0':
result = '0' + result
print(result)
if carry == True:
result = '1' + result
else:
result = '0' + result
return result
print(addBinary('10110101','10010001'))
and the output is
0
10
110
0110
10110
110110
0110110
00110110
000110110
the correct output is 0101000110
You're doing your math in the wrong direction. Your code starts at the most significant place value, and works backwards.
Ie Your example is actually doing 10101101 + 10001001.
Change your for loop to: for i in range(len(x) - 1, -1, -1): OR reverse your inputs with x = x[::-1] and y = y[::-1].
Also your last if statement should be if carry: since it's either true or false, not 1 or 0.