README.md

1342. Number of Steps to Reduce a Number to Zero

Given a non-negative integer num, return the number of steps to reduce it to zero. If the current number is even, you have to divide it by 2, otherwise, you have to subtract 1 from it.

Example 1:

Input: num = 14
Output: 6
Explanation:
Step 1) 14 is even; divide by 2 and obtain 7.
Step 2) 7 is odd; subtract 1 and obtain 6.
Step 3) 6 is even; divide by 2 and obtain 3.
Step 4) 3 is odd; subtract 1 and obtain 2.
Step 5) 2 is even; divide by 2 and obtain 1.
Step 6) 1 is odd; subtract 1 and obtain 0.

Example 2:

Input: num = 8
Output: 4
Explanation:
Step 1) 8 is even; divide by 2 and obtain 4.
Step 2) 4 is even; divide by 2 and obtain 2.
Step 3) 2 is even; divide by 2 and obtain 1.
Step 4) 1 is odd; subtract 1 and obtain 0.

Example 3:

Input: num = 123
Output: 12

Constraints:

• 0 <= num <= 10^6

Solutions (Ruby)

1. Simulation

# @param {Integer} num
# @return {Integer}
def number_of_steps (num)
    ret = 0

    while num != 0
        if num % 2 == 0
            num /= 2
        else
            num -= 1
        end
        ret += 1
    end

    return ret
end

Solutions (Rust)

1. Simulation

impl Solution {
    pub fn number_of_steps (num: i32) -> i32 {
        let mut num = num;
        let mut ret = 0;

        while num != 0 {
            match num % 2 {
                0 => num /= 2,
                _ => num -= 1,
            }
            ret += 1;
        }

        ret
    }
}