문제
지정된 정수 값을 0으로 줄일 단계 수를 반환합니다.
한 단계에서는 현재 숫자가 짝수이면 2로 나누어야 하고, 그렇지 않으면 1을 빼야 한다.
https://leetcode.com/problems/number-of-steps-to-reduce-a-number-to-zero/
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
풀이
class Solution {
public int numberOfSteps(int num) {
int res=0;
while(num!=0){
num=(num%2==0)?num/2:num-1;
res++;
}
return res;
}
}