New Problem Solution - "Maximum Absolute Sum of Any Subarray"

Author: haoel

README.md

@@ -12,6 +12,7 @@ LeetCode
 |1754|[Largest Merge Of Two Strings](https://leetcode.com/problems/largest-merge-of-two-strings/) | [C++](./algorithms/cpp/largestMergeOfTwoStrings/LargestMergeOfTwoStrings.cpp)|Medium|
 |1753|[Maximum Score From Removing Stones](https://leetcode.com/problems/maximum-score-from-removing-stones/) | [C++](./algorithms/cpp/maximumScoreFromRemovingStones/MaximumScoreFromRemovingStones.cpp)|Medium|
 |1752|[Check if Array Is Sorted and Rotated](https://leetcode.com/problems/check-if-array-is-sorted-and-rotated/) | [C++](./algorithms/cpp/checkIfArrayIsSortedAndRotated/CheckIfArrayIsSortedAndRotated.cpp)|Easy|
+|1749|[Maximum Absolute Sum of Any Subarray](https://leetcode.com/problems/maximum-absolute-sum-of-any-subarray/) | [C++](./algorithms/cpp/maximumAbsoluteSumOfAnySubarray/MaximumAbsoluteSumOfAnySubarray.cpp)|Medium|
 |1748|[Sum of Unique Elements](https://leetcode.com/problems/sum-of-unique-elements/) | [C++](./algorithms/cpp/sumOfUniqueElements/SumOfUniqueElements.cpp)|Easy|
 |1605|[Find Valid Matrix Given Row and Column Sums](https://leetcode.com/problems/find-valid-matrix-given-row-and-column-sums/) | [C++](./algorithms/cpp/FindValidMatrixGivenRowAndColumnSums/FindValidMatrixGivenRowAndColumnSums.cpp)|Medium|
 |1573|[Number of Ways to Split a String](https://leetcode.com/problems/number-of-ways-to-split-a-string/) | [C++](./algorithms/cpp/NumberOfWaysToSplitString/NumberOfWaysToSplitString.cpp)|Medium|

algorithms/cpp/maximumAbsoluteSumOfAnySubarray/MaximumAbsoluteSumOfAnySubarray.cpp

@@ -0,0 +1,96 @@
+// Source : https://leetcode.com/problems/maximum-absolute-sum-of-any-subarray/
+// Author : Hao Chen
+// Date   : 2021-02-12
+
+/***************************************************************************************************** 
+ *
+ * You are given an integer array nums. The absolute sum of a subarray [numsl, numsl+1, ..., numsr-1, 
+ * numsr] is abs(numsl + numsl+1 + ... + numsr-1 + numsr).
+ * 
+ * Return the maximum absolute sum of any (possibly empty) subarray of nums.
+ * 
+ * Note that abs(x) is defined as follows:
+ * 
+ * 	If x is a negative integer, then abs(x) = -x.
+ * 	If x is a non-negative integer, then abs(x) = x.
+ * 
+ * Example 1:
+ * 
+ * Input: nums = [1,-3,2,3,-4]
+ * Output: 5
+ * Explanation: The subarray [2,3] has absolute sum = abs(2+3) = abs(5) = 5.
+ * 
+ * Example 2:
+ * 
+ * Input: nums = [2,-5,1,-4,3,-2]
+ * Output: 8
+ * Explanation: The subarray [-5,1,-4] has absolute sum = abs(-5+1-4) = abs(-8) = 8.
+ * 
+ * Constraints:
+ * 
+ * 	1 <= nums.length <= 105
+ * 	-104 <= nums[i] <= 104
+ ******************************************************************************************************/
+
+class Solution {
+public:
+    int maxAbsoluteSum(vector<int>& nums) {
+        return maxAbsoluteSum02(nums); //56ms
+        return maxAbsoluteSum01(nums); //56ms
+    }
+    
+    
+    
+    int maxAbsoluteSum01(vector<int>& nums) {
+        return std::max(maxSumArray(nums), std::abs(minSumArray(nums)) );
+    }
+    
+    //https://en.wikipedia.org/wiki/Maximum_subarray_problem
+    int maxSumArray(vector<int>& nums) {
+        int max = nums[0];
+        int sum = nums[0];
+        for (int i = 1; i < nums.size(); i++) {
+            if (sum < 0 ) sum = nums[i];
+            else sum += nums[i];
+            if (max < sum) max = sum;
+        }
+        return max;
+    }
+    
+    int minSumArray(vector<int>& nums) {
+        int min = nums[0];
+        int sum = nums[0];
+        for (int i = 1; i < nums.size(); i++) {
+            if (sum > 0 ) sum = nums[i];
+            else sum += nums[i];
+            if (min > sum) min = sum;
+        }
+        return min;
+    }
+    
+    // Becasue maxSumArray() & minSumArray() are two similar,
+    // we can merge them together to save one loop
+    int maxAbsoluteSum02(vector<int>& nums) {
+        int max = nums[0];
+        int max_sum = nums[0];
+        
+        int min = nums[0];
+        int min_sum = nums[0];
+        
+        for (int i = 1; i < nums.size(); i++) {
+            
+            if (max_sum < 0 ) max_sum = nums[i];
+            else max_sum += nums[i];
+            if (max < max_sum) max = max_sum;
+            
+            
+            if (min_sum > 0 ) min_sum = nums[i];
+            else min_sum += nums[i];
+            if (min > min_sum) min = min_sum;
+            
+        }
+        
+        return std::max(max, abs(min));
+    }
+    
+};