Create find-latest-group-of-size-m.cpp

Author: kamyu104

C++/find-latest-group-of-size-m.cpp

@@ -0,0 +1,21 @@
+// Time:  O(n)
+// Space: O(n)
+
+class Solution {
+public:
+    int findLatestStep(vector<int>& arr, int m) {
+        int result = -1;
+        if (m == arr.size()) {
+            return m;
+        }
+        vector<int> length(arr.size() + 2);
+        for (int i = 0; i < arr.size(); ++i) {
+            int x = arr[i], left = length[x - 1], right = length[x + 1];
+            if (left == m || right == m) {
+                result = i;
+            }
+            length[x - left] = length[x + right] = left + right + 1;
+        }
+        return result;
+    }
+};