In this guide we will provide 7. Reverse Integer LeetCode Solution with best time and space complexity. The solution to Reverse Integer problem is provided in various programming languages like C++, Java and python. This will be helpful for you if you are preparing for placements, hackathon, interviews or practice purposes. The solutions provided here are very easy to follow and with detailed explanations.
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
Constraints:
-231 <= x <= 231 – 1
Complexity Analysis
Time Complexity: O(\log x)
Space Complexity: O(1)
7. Reverse Integer LeetCode Solution in C++
class Solution {
public:
int reverse(int x) {
long ans = 0;
while (x != 0) {
ans = ans * 10 + x % 10;
x /= 10;
}
return (ans < INT_MIN || ans > INT_MAX) ? 0 : ans;
}
}; /* code provided by PROGIEZ */
7. Reverse Integer LeetCode Solution in Java
class Solution {
public int reverse(int x) {
long ans = 0;
while (x != 0) {
ans = ans * 10 + x % 10;
x /= 10;
}
return (ans < Integer.MIN_VALUE || ans > Integer.MAX_VALUE) ? 0 : (int) ans;
}
} // code provided by PROGIEZ
7. Reverse Integer LeetCode Solution in Python
class Solution:
def reverse(self, x: int) -> int:
ans = 0
sign = -1 if x < 0 else 1
x *= sign
while x:
ans = ans * 10 + x % 10
x //= 10
return 0 if ans < -2**31 or ans > 2**31 - 1 else sign * ans #code by PROGIEZ
