Create can-make-arithmetic-progression-from-sequence.cpp

Author: kamyu104

C++/can-make-arithmetic-progression-from-sequence.cpp

@@ -0,0 +1,25 @@
+// Time:  O(n)
+// Space: O(1)
+
+class Solution {
+public:
+    bool canMakeArithmeticProgression(vector<int>& arr) {
+        const auto m = *min_element(cbegin(arr), cend(arr));
+        const auto& d = (*max_element(cbegin(arr), cend(arr)) - m) / (arr.size() - 1);
+        if (!d) {
+            return true;
+        }
+        for (int i = 0; i < arr.size();) {
+            if (arr[i] == m + i * d) {
+                ++i;
+            } else {
+                const auto& diff = arr[i] - m;
+                if (diff % d || diff / d >= arr.size() || arr[i] == arr[diff / d]) {
+                    return false;
+                }
+                swap(arr[i], arr[diff / d]);
+            }
+        }
+        return true;
+    }
+};