Create find-k-closest-elements.cpp

Author: kamyu104

C++/find-k-closest-elements.cpp

@@ -0,0 +1,14 @@
+// Time:  O(logn + k)
+// Space: O(1)
+
+class Solution {
+public:
+    vector<int> findClosestElements(vector<int>& arr, int k, int x) {
+        auto i = distance(arr.begin(), lower_bound(arr.begin(), arr.end(), x));
+        int left = i - 1, right = i;                                    
+        while (k--) {
+            (right >= arr.size() || (left >= 0 && abs(arr[left] - x) <= abs(arr[right] - x) )) ? --left : ++right;
+        }
+        return vector<int>(arr.begin() + left + 1, arr.begin() + right);
+    }
+};