1523. Count Odd Numbers in an Interval Range

Problem Statement

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

 

Example 1:

Input: low = 3, high = 7
Output: 3
Explanation: The odd numbers between 3 and 7 are [3,5,7].```

<p><strong class="example">Example 2:</strong></p>

Input: low = 8, high = 10 Output: 1 Explanation: The odd numbers between 8 and 10 are [9].```

 

Constraints:

• 0 <= low <= high <= 10^9

Click to open Hints

• If the range (high - low + 1) is even, the number of even and odd numbers in this range will be the same.
• If the range (high - low + 1) is odd, the solution will depend on the parity of high and low.

Solution:

Rust

impl Solution {
    pub fn count_odds(low: i32, high: i32) -> i32 {
        // ((high + 1) / 2) - (low / 2)
        ((high + 1) >> 1) - (low >> 1) // same as above
    }
}

Go

package main

func countOdds(low int, high int) int {
	return ((high + 1) / 2) - (low / 2)
}

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