Add Maximum Array Rotation in C++ (#5172)

Author: Jake-G123

archive/c/c-plus-plus/maximum-array-rotation.cpp

@@ -0,0 +1,44 @@
+#include <iostream>
+#include <vector>
+#include <sstream>
+
+using namespace std;
+int main(int argc, char *argv[]) {
+    // Check if input exists and isn't empty
+    if (argc < 2 || string(argv[1]).empty()) {
+        cout << "Usage: please provide a list of integers (e.g. \"8, 3, 1, 2\")";
+        return 1;
+    }
+    // Parse input string
+    vector<int> arr;
+    string input = argv[1];
+    stringstream ss(input);
+    string token;
+
+    while (getline(ss, token, ',')) {
+        arr.push_back(stoi(token));
+    }
+
+    int n = arr.size();
+    int arr_sum = 0;
+    int current_sum = 0;
+    // Get sum of array and first rotation sum
+    for (int i = 0; i < n; i++) {
+        arr_sum += arr[i];
+        current_sum+= i * arr[i];
+    }
+    
+    int max_sum = current_sum;
+    // check all other possible rotations
+    for (int j = 1; j < n; j++) {
+        int rotating_value = arr[n-j];
+        // next sum = current sum + gains of shifting values one index higher - loss of moving highest index to 0
+        current_sum = current_sum + arr_sum - n * rotating_value;
+
+        if (current_sum > max_sum) {
+            max_sum = current_sum;
+        }
+    }
+    cout << max_sum << endl;
+    return 0;
+}