Problem
Given an integer num
, return the number of steps to reduce it to zero.
In one step, 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
Constraint:
0 <= num <= 10^6
Solution
/**
* @param {number} num
* @return {number}
*/
var numberOfSteps = function(num) {
let ans = 0
for (; num; ans++)
if (num % 2) num--
else num /= 2
return ans
};