Create MaxProductOfSubArray.cpp

MaxProductOfSubArray.cpp

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+#include <bits/stdc++.h> 
+using namespace std; 
+
+/* Returns the product of max product subarray.  
+Assumes that the given array always has a subarray  
+with product more than 1 */
+int maxSubarrayProduct(int arr[], int n) 
+{ 
+    // max positive product ending at the current position 
+    int max_ending_here = 1; 
+
+    // min negative product ending at the current position 
+    int min_ending_here = 1; 
+
+    // Initialize overall max product 
+    int max_so_far = 1; 
+    int flag = 0; 
+    for (int i = 0; i < n; i++) { 
+        if (arr[i] > 0) { 
+            max_ending_here = max_ending_here * arr[i]; 
+            min_ending_here = min(min_ending_here * arr[i], 1); 
+            flag = 1; 
+        } 
+        else if (arr[i] == 0) { 
+            max_ending_here = 1; 
+            min_ending_here = 1; 
+        } 
+        else { 
+            int temp = max_ending_here; 
+            max_ending_here = max(min_ending_here * arr[i], 1); 
+            min_ending_here = temp * arr[i]; 
+        } 
+        if (max_so_far < max_ending_here) 
+            max_so_far = max_ending_here; 
+    } 
+    if (flag == 0 && max_so_far == 1) 
+        return 0; 
+    return max_so_far; 
+} 
+
+int main() 
+{ 
+    int arr[] = { 1, -2, -3, 0, 7, -8, -2 }; 
+    int n = sizeof(arr) / sizeof(arr[0]); 
+    cout << "Maximum Sub array product is "
+         << maxSubarrayProduct(arr, n); 
+    return 0; 
+}