Determine whether an integer is a palindrome. Do this without extra space.
C Solution:
bool isPalindrome(int x) {
if (x < 0) return false;
if (x && x % 10 == 0) return false;
int y = 0;
while (x > y) {
y = y * 10 + x % 10;
x /= 10;
}
return x == y || x == y / 10;
}
Summary:
- When
x < 0, return false..., this should be clarified. - The only special case is when the least-significant digit is 0. Remember.
LeetCode: 9. Palindrome Number
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