1342. Number of Steps to Reduce a Number to Zero

Link: https://leetcode.com/problems/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

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題目翻譯:

X

程式思路:

直接硬幹

class Solution {
public:
    int numberOfSteps (int num) {
        int output = 0;
        while(num != 0)
        {
            if(num%2 == 1)
                num--;
            else
                num >>= 1;
            output ++;
        }
        return output;
    }
};