1342. Number of Steps to Reduce a Number to Zero

标签：xpl   ret   nts   public   Plan   number   while   and   constrain   

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

class Solution {
    public int numberOfSteps (int num) {
        int k = num;
        int res = 0;
        while(k != 0){
            if(k % 2 != 0){
                res++;
                k--;
            }
            else {
                res++;
                k /= 2;
            }
        }
        return res;
    }
}

1342. Number of Steps to Reduce a Number to Zero

标签：xpl   ret   nts   public   Plan   number   while   and   constrain   

原文地址：https://www.cnblogs.com/wentiliangkaihua/p/12289730.html