feat: 53_maximum_subarray

53_maximum_subarray/main.cpp

@@ -0,0 +1,32 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+class Solution {
+   public:
+    int maxSubArray(vector<int>& nums) {
+        return maxSubArray(nums, 0, nums.size() - 1);
+    }
+
+    int maxSubArray(vector<int>& nums, int leftIndex, int rightIndex) {
+        if (leftIndex > rightIndex) return INT32_MIN;
+
+        int mid = (leftIndex + rightIndex) / 2;
+        int leftMaxSum = 0, rightMaxSum = 0;
+
+        // left half side sum
+        for (int i = mid - 1, currentSum = 0; i >= leftIndex; i--) {
+            currentSum += nums[i];
+            leftMaxSum = max(leftMaxSum, currentSum);
+        }
+
+        // right half side sum
+        for (int i = mid + 1, currentSum = 0; i <= rightIndex; i++) {
+            currentSum += nums[i];
+            rightMaxSum = max(rightMaxSum, currentSum);
+        }
+
+        return max(max(maxSubArray(nums, leftIndex, mid - 1),
+                       maxSubArray(nums, mid + 1, rightIndex)),
+                   leftMaxSum + nums[mid] + rightMaxSum);
+    }
+};