day 12

Author: sachuverma

Leetcode Daily Challenge/February-2021/12. Number of Steps to Reduce a Number to Zero.cpp

@@ -0,0 +1,52 @@
+/*
+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
+
+Hint #1  
+Simulate the process to get the final answer.
+*/
+
+class Solution
+{
+public:
+  int numberOfSteps(int num)
+  {
+    if (num == 0)
+      return 0;
+    int ans = 0;
+    if (num % 2 == 0)
+      ans += numberOfSteps(num / 2);
+    else
+      ans += numberOfSteps(num - 1);
+    return ans + 1;
+  }
+};

Leetcode Daily Challenge/February-2021/README.MD

@@ -13,5 +13,6 @@
 | 9.  | [Convert BST to Greater Tree](https://leetcode.com/explore/challenge/card/february-leetcoding-challenge-2021/585/week-2-february-8th-february-14th/3634/) | [cpp](./09.%20Convert%20BST%20to%20Greater%20Tree.cpp) | 
 | 10.  | [Copy List with Random Pointer](https://leetcode.com/explore/challenge/card/february-leetcoding-challenge-2021/585/week-2-february-8th-february-14th/3635/) | [cpp](./10.%20Copy%20List%20with%20Random%20Pointer.cpp) | 
 | 11.  | [Valid Anagram](https://leetcode.com/explore/challenge/card/february-leetcoding-challenge-2021/585/week-2-february-8th-february-14th/3636/) | [cpp](./11.%20Valid%20Anagram.cpp) | 
+| 12.  | [Number of Steps to Reduce a Number to Zero](https://leetcode.com/explore/challenge/card/february-leetcoding-challenge-2021/585/week-2-february-8th-february-14th/3637/) | [cpp](./12.%20Number%20of%20Steps%20to%20Reduce%20a%20Number%20to%20Zero.cpp) |