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.
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.
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.
Input: num = 123 Output: 12
0 <= num <= 10^6
# @param {Integer} num# @return {Integer}defnumber_of_steps(num)ret=0whilenum != 0ifnum % 2 == 0num /= 2elsenum -= 1endret += 1endreturnretend
implSolution{pubfnnumber_of_steps(num:i32) -> i32{letmut num = num;letmut ret = 0;while num != 0{match num % 2{0 => num /= 2, _ => num -= 1,} ret += 1;} ret }}