7. Reverse Integer
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Given a signed 32-bit integer x, return x with its digits reversed. If reversing x causes the value to go outside the signed 32-bit integer range [-231, 231 - 1], then return 0.
Assume the environment does not allow you to store 64-bit integers (signed or unsigned).
Example 1:
Input: x = 123 Output: 321
Example 2:
Input: x = -123 Output: -321
Example 3:
Input: x = 120 Output: 21
First accepted
Idea:
- Convert number to int
- Remove
minusif exist (or convert module of number) - reverse
class Solution:
def reverse(self, x: int) -> int:
reversed_int = []
str_int = str(x)
if x < 0:
str_int = str_int[1:]
for i in reversed(range(len(str_int))):
reversed_int.append(str_int[i])
res = int(''.join(reversed_int))
if x < 0:
res = -res
return res if (res >= -2147483648 and res <= 2147483647) else 0
Better solution
class Solution:
def reverse(self, x: int) -> int:
s = str(abs(x))
rev = int(s[::-1])
if rev > 2147483647:
return 0
return rev if x > 0 else (rev * -1)
