New Problem Solution - "1529. Bulb Switcher IV"

Author: haoel

README.md

@@ -72,6 +72,7 @@ LeetCode
 |1550|[Three Consecutive Odds](https://leetcode.com/problems/three-consecutive-odds/) | [C++](./algorithms/cpp/threeConsecutiveOdds/ThreeConsecutiveOdds.cpp)|Easy|
 |1541|[Minimum Insertions to Balance a Parentheses String](https://leetcode.com/problems/minimum-insertions-to-balance-a-parentheses-string/) | [C++](./algorithms/cpp/minimumInsertionsToBalanceAParenthesesString/MinimumInsertionsToBalanceAParenthesesString.cpp)|Medium|
 |1535|[Find the Winner of an Array Game](https://leetcode.com/problems/find-the-winner-of-an-array-game/) | [C++](./algorithms/cpp/findTheWinnerOfAnArrayGame/FindTheWinnerOfAnArrayGame.cpp)|Medium|
+|1529|[Bulb Switcher IV](https://leetcode.com/problems/bulb-switcher-iv/) | [C++](./algorithms/cpp/bulbSwitcher/BulbSwitcher.IV.cpp)|Medium|
 |1528|[Shuffle String](https://leetcode.com/problems/shuffle-string/submissions/) | [C++](./algorithms/cpp/shuffleString/ShuffleString.cpp)|Easy|
 |1525|[Number of Good Ways to Split a String](https://leetcode.com/problems/number-of-good-ways-to-split-a-string/) | [C++](./algorithms/cpp/numberOfGoodWaysToSplitAString/NumberOfGoodWaysToSplitAString.cpp)|Medium|
 |1524|[Number of Sub-arrays With Odd Sum](https://leetcode.com/problems/number-of-sub-arrays-with-odd-sum/) | [C++](./algorithms/cpp/numberOfSubArraysWithOddSum/NumberOfSubArraysWithOddSum.cpp)|Medium|

algorithms/cpp/bulbSwitcher/BulbSwitcher.IV.cpp

@@ -0,0 +1,65 @@
+// Source : https://leetcode.com/problems/bulb-switcher-iv/
+// Author : Hao Chen
+// Date   : 2021-03-29
+
+/***************************************************************************************************** 
+ *
+ * There is a room with n bulbs, numbered from 0 to n-1, arranged in a row from left to right. 
+ * Initially all the bulbs are turned off.
+ * 
+ * Your task is to obtain the configuration represented by target where target[i] is '1' if the i-th 
+ * bulb is turned on and is '0' if it is turned off.
+ * 
+ * You have a switch to flip the state of the bulb, a flip operation is defined as follows:
+ * 
+ * 	Choose any bulb (index i) of your current configuration.
+ * 	Flip each bulb from index i to n-1.
+ * 
+ * When any bulb is flipped it means that if it is 0 it changes to 1 and if it is 1 it changes to 0.
+ * 
+ * Return the minimum number of flips required to form target.
+ * 
+ * Example 1:
+ * 
+ * Input: target = "10111"
+ * Output: 3
+ * Explanation: Initial configuration "00000".
+ * flip from the third bulb:  "00000" -> "00111"
+ * flip from the first bulb:  "00111" -> "11000"
+ * flip from the second bulb:  "11000" -> "10111"
+ * We need at least 3 flip operations to form target.
+ * 
+ * Example 2:
+ * 
+ * Input: target = "101"
+ * Output: 3
+ * Explanation: "000" -> "111" -> "100" -> "101".
+ * 
+ * Example 3:
+ * 
+ * Input: target = "00000"
+ * Output: 0
+ * 
+ * Example 4:
+ * 
+ * Input: target = "001011101"
+ * Output: 5
+ * 
+ * Constraints:
+ * 
+ * 	1 <= target.length <= 10^5
+ * 	target[i] == '0' or target[i] == '1'
+ ******************************************************************************************************/
+
+class Solution {
+public:
+    int minFlips(string target) {
+        //flip the target to initalization
+        int flip = 0;
+        for(auto state : target) {
+            if (state == '0' && flip % 2 == 1 ) flip++;
+            if (state == '1' && flip % 2 == 0 ) flip++;
+        }
+        return flip;
+    }
+};