Leetcode 1523. Count Odd Numbers in an Interval Range

Given two non-negative integers `low` and `high`. Return the count of odd numbers between `low` and `high` (inclusive). 　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

Programming Skills I Easy

Description

Given two non-negative integers low and high. Return the count of odd numbers between low and high (inclusive).

Example 1:

Input: low = 3, high = 7
Output: 3

• The odd numbers between 3 and 7 are [3,5,7].

Example 2:

Input: low = 8, high = 10
Output: 1

• The odd numbers between 8 and 10 are [9].

Constraints:

• 0 <= low <= high <= 10^9

Solution

class Solution:
    # Mathematical Approach
    # Time Complexity: BigO(1)
    # Space Complexity: BigO(1)
    def countOdds(self, low: int, high: int) -> int:
        is_odd = 1 if high % 2 == 1 or low % 2 == 1 else 0
        return (high - low)//2 + is_odd

• //: divide with integral result (discard remainder)

/**
 * Mathematical Approach
 * Time Complexity: BigO(1)
 * Space Complexity: BigO(1)
 */
function countOdds(low: number, high: number): number {
  let includes = high % 2 == 1 || low % 2 == 1 ? 1 : 0;
  return Math.floor((high - low) / 2) + includes;
}