# Palindrome Number Leetcode Solution | Easy Approach

Share:

Palindrome Number Leetcode | Given an integer `x`, return `true` if `x` is palindrome integer.

An integer is a palindrome when it reads the same backward as forward.

• For example, `121` is a palindrome while `123` is not.

Example 1:

```Input: x = 121
Output: true
Explanation: 121 reads as 121 from left to right and from right to left.
```

Example 2:

```Input: x = -121
Output: false
Explanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.
```

Example 3:

```Input: x = 10
Output: false
Explanation: Reads 01 from right to left. Therefore it is not a palindrome.
```

Constraints:

• `-231 <= x <= 231 - 1`

Time: O(logx)
Space: O(logx)

### C++

``````class Solution {
public:
bool isPalindrome(int x) {
if (x < 0)
return false;

long reversed = 0;
int y = x;

while (y) {
reversed = reversed * 10 + y % 10;
y /= 10;
}

return reversed == x;
}
};
``````

### Java

``````class Solution {
public boolean isPalindrome(int x) {
if (x < 0)
return false;

long reversed = 0;
int y = x;

while (y > 0) {
reversed = reversed * 10 + y % 10;
y /= 10;
}

return reversed == x;
}
}
``````

### Python

``````class Solution:
def twoSum(self, nums: List[int], target: int) -> List[int]:
numToIndex = {}

for i, num in enumerate(nums):
if target - num in numToIndex:
return numToIndex[target - num], i
numToIndex[num] = i
``````

#### Watch Tutorial

Checkout more Solutions here