2180. Count Integers With Even Digit Sum LeetCode Solution
In this guide, you will get 2180. Count Integers With Even Digit Sum LeetCode Solution with the best time and space complexity. The solution to Count Integers With Even Digit Sum problem is provided in various programming languages like C++, Java, and Python. This will be helpful for you if you are preparing for placements, hackathons, interviews, or practice purposes. The solutions provided here are very easy to follow and include detailed explanations.
Problem Statement of Count Integers With Even Digit Sum
Given a positive integer num, return the number of positive integers less than or equal to num whose digit sums are even.
The digit sum of a positive integer is the sum of all its digits.
Example 1:
Input: num = 4
Output: 2
Explanation:
The only integers less than or equal to 4 whose digit sums are even are 2 and 4.
Example 2:
Input: num = 30
Output: 14
Explanation:
The 14 integers less than or equal to 30 whose digit sums are even are
2, 4, 6, 8, 11, 13, 15, 17, 19, 20, 22, 24, 26, and 28.
Constraints:
1 <= num <= 1000
Complexity Analysis
Time Complexity: O(\log\texttt{num})
Space Complexity: O(1)
2180. Count Integers With Even Digit Sum LeetCode Solution in C++
class Solution {
public:
int countEven(int num) {
return (num - getDigitSum(num) % 2) / 2;
}
private:
int getDigitSum(int num) {
int digitSum = 0;
while (num > 0) {
digitSum += num % 10;
num /= 10;
}
return digitSum;
}
}; /* code provided by PROGIEZ */
2180. Count Integers With Even Digit Sum LeetCode Solution in Java
class Solution {
public int countEven(int num) {
if (getDigitSum(num) % 2 == 0)
return num / 2;
return (num - 1) / 2;
}
private int getDigitSum(int num) {
int digitSum = 0;
while (num > 0) {
digitSum += num % 10;
num /= 10;
}
return digitSum;
}
} // code provided by PROGIEZ
2180. Count Integers With Even Digit Sum LeetCode Solution in Python
class Solution:
def countEven(self, num: int) -> int:
return (num - self._getDigitSum(num) % 2) // 2
def _getDigitSum(self, num: int) -> int:
return sum(int(digit) for digit in str(num)) # code by PROGIEZ
